client.test.ts

/* eslint-disable @typescript-eslint/no-explicit-any */
import { EventEmitter, once } from "node:events";
import { PassThrough } from "stream";
import { existsSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
import { createRequire } from "node:module";
import { createConnection, createServer, type Socket } from "node:net";
import { tmpdir } from "node:os";
import { join, resolve } from "node:path";
import { describe, expect, it, onTestFinished, vi } from "vitest";
import {
    createMessageConnection,
    StreamMessageReader,
    StreamMessageWriter,
    type MessageConnection,
} from "vscode-jsonrpc/node.js";
import {
    approveAll,
    createAttributedPermissionResult,
    CopilotClient,
    createCanvas,
    DisableBypassPermissionsModes,
    RuntimeConnection,
    type CapiSessionOptions,
    type CopilotClientOptions,
    type GitHubTelemetryNotification,
    type ManagedSettings,
    type ModelInfo,
    type SubagentStartHookOutput,
    type SubagentStopHookOutput,
    type SessionFsProvider,
} from "../src/index.js";
import { CopilotSession } from "../src/session.js";
import { defaultJoinSessionPermissionHandler } from "../src/types.js";
import { getSdkProtocolVersion } from "../src/sdkProtocolVersion.js";

// This file is for unit tests. Where relevant, prefer to add e2e tests in e2e/*.test.ts instead

async function stopClient(client: CopilotClient): Promise<void> {
    await client.stop();
}

describe("approveAll", () => {
    const request = {
        kind: "url" as const,
        url: "https://api.example.com/data",
        intention: "Fetch domain data",
    };
    const invocation = { sessionId: "session-1", managedSettingsEnabled: false };

    it("approves ordinary permission requests", () => {
        expect(approveAll(request, invocation)).toEqual({ kind: "approve-once" });
    });

    it("rejects managed settings sessions", () => {
        expect(() => approveAll(request, { ...invocation, managedSettingsEnabled: true })).toThrow(
            "approveAll cannot be used when managed settings are enabled"
        );
    });

    it("leaves managed requests pending when managed settings are disabled", () => {
        expect(approveAll({ ...request, managedApprovalRequired: true }, invocation)).toEqual({
            kind: "no-result",
        });
    });

    it("fails closed when managed approval metadata is malformed", () => {
        const malformedRequest = {
            ...request,
            managedApprovalRequired: "yes",
        } as unknown as Parameters<typeof approveAll>[0];

        expect(approveAll(malformedRequest, invocation)).toEqual({ kind: "no-result" });
    });
});

describe("CopilotClient", () => {
    it("start() is single-flight: concurrent callers share one startup", async () => {
        const client = new CopilotClient({ autoStart: false });
        onTestFinished(() => client.forceStop());

        // Stub the underlying startup (doStart) that the single-flight guard
        // dedupes. Transport-independent: this is the same regardless of the
        // stdio vs in-process connection path. The delay makes all three
        // start() calls overlap; on success it marks the client connected like
        // the real doStart does.
        const doStart = vi.fn().mockImplementation(
            () =>
                new Promise<void>((resolve) =>
                    setTimeout(() => {
                        (client as any).state = "connected";
                        resolve();
                    }, 50)
                )
        );
        (client as any).doStart = doStart;

        // Before the fix, each concurrent caller ran startup (and spawned its own
        // CLI, orphaning all but the last). With single-flight they share one.
        await Promise.all([client.start(), client.start(), client.start()]);

        expect(doStart).toHaveBeenCalledTimes(1);
        expect((client as any).state).toBe("connected");

        // Once connected, a further start() is a no-op (no extra startup).
        await client.start();
        expect(doStart).toHaveBeenCalledTimes(1);
    });

    it("start() retries after a failed attempt (single-flight guard is cleared)", async () => {
        const client = new CopilotClient({ autoStart: false });
        onTestFinished(() => client.forceStop());

        // Stub the underlying startup: fail once, then succeed. Transport-
        // independent (does not depend on the stdio vs in-process path).
        const doStart = vi
            .fn()
            .mockImplementationOnce(async () => {
                (client as any).state = "error";
                throw new Error("boom");
            })
            .mockImplementationOnce(async () => {
                (client as any).state = "connected";
            });
        (client as any).doStart = doStart;

        await expect(client.start()).rejects.toThrow(/boom/);
        expect((client as any).state).toBe("error");

        // The guard must have cleared so a later start() can retry.
        await client.start();
        expect(doStart).toHaveBeenCalledTimes(2);
        expect((client as any).state).toBe("connected");
    });

    it.each([
        {
            source: "connection path",
            connection: RuntimeConnection.forStdio({ path: "/explicit/copilot" }),
            env: {},
            expected: "/explicit/copilot",
        },
        {
            source: "COPILOT_CLI_PATH",
            connection: RuntimeConnection.forStdio(),
            env: { COPILOT_CLI_PATH: "/environment/copilot" },
            expected: "/environment/copilot",
        },
    ])(
        "preserves explicit child-process override from $source",
        ({ connection, env, expected }) => {
            const client = new CopilotClient({ connection, env });

            expect((client as any).resolvedCliPath).toBe(expected);
        }
    );

    async function startWithMockConnection(
        builtinPluginDirectories?: readonly string[]
    ): Promise<ReturnType<typeof vi.fn>> {
        const client = new CopilotClient({
            connection: RuntimeConnection.forUri("localhost:1234"),
            builtinPluginDirectories,
        });
        const sendRequest = vi.fn(async () => ({}));
        vi.spyOn(client as any, "connectToServer").mockImplementation(async () => {
            (client as any).connection = { sendRequest };
        });
        vi.spyOn(client as any, "verifyProtocolVersion").mockResolvedValue(undefined);

        await client.start();
        return sendRequest;
    }

    it.each([undefined, []])(
        "does not configure built-in plugin directories when unset or empty",
        async (builtinPluginDirectories) => {
            const sendRequest = await startWithMockConnection(builtinPluginDirectories);

            expect(sendRequest).not.toHaveBeenCalledWith("plugins.builtin.set", expect.anything());
        }
    );

    it("configures built-in plugin directories before start completes", async () => {
        const paths = [resolve("plugins/core"), resolve("plugins/github")];

        const sendRequest = await startWithMockConnection(paths);

        expect(sendRequest).toHaveBeenCalledTimes(1);
        expect(sendRequest).toHaveBeenCalledWith("plugins.builtin.set", { paths });
    });

    it("rejects relative built-in plugin directories", () => {
        expect(
            () =>
                new CopilotClient({
                    connection: RuntimeConnection.forUri("localhost:1234"),
                    builtinPluginDirectories: ["plugins/core"],
                })
        ).toThrow(/builtinPluginDirectories.*absolute paths.*plugins\/core/);
    });

    it("disposes the stdio connection when child stdin emits an error", async () => {
        const client = new CopilotClient();
        onTestFinished(() => client.forceStop());

        const stdin = new PassThrough();
        const stdout = new PassThrough();
        (client as any).cliProcess = Object.assign(new EventEmitter(), { stdin, stdout });
        await (client as any).connectToChildProcessViaStdio();

        const dispose = vi.spyOn((client as any).connection, "dispose");

        const boom = new Error("broken pipe");
        expect(() => stdin.emit("error", boom)).not.toThrow();
        expect(dispose).toHaveBeenCalledOnce();
    });

    it("does not respond to v3 permission requests when handler returns no-result", async () => {
        const session = new CopilotSession("session-1", {} as any);
        session.registerPermissionHandler(() => ({ kind: "no-result" }));
        const spy = vi.spyOn(session.rpc.permissions, "handlePendingPermissionRequest");

        await (session as any)._executePermissionAndRespond("request-1", { kind: "write" });

        expect(spy).not.toHaveBeenCalled();
    });

    it("forwards decisionContext as a top-level sibling of result", async () => {
        const session = new CopilotSession("session-1", {} as any);
        const decisionContext = {
            outcome: "auto_approved" as const,
            source: "host_policy" as const,
            surface: "sdk" as const,
        };
        session.registerPermissionHandler(() =>
            createAttributedPermissionResult({ kind: "approve-once" }, decisionContext)
        );
        const spy = vi
            .spyOn(session.rpc.permissions, "handlePendingPermissionRequest")
            .mockResolvedValue({ kind: "approve-once" } as any);

        await (session as any)._executePermissionAndRespond("request-1", { kind: "write" });

        expect(spy).toHaveBeenCalledOnce();
        const params = spy.mock.calls[0][0] as any;
        expect(params).toEqual({
            requestId: "request-1",
            result: { kind: "approve-once" },
            decisionContext,
        });
        // decisionContext is a sibling of result, never nested inside it.
        expect(params.result.decisionContext).toBeUndefined();
    });

    it("emits exactly requestId and result with no decisionContext key when unattributed", async () => {
        const session = new CopilotSession("session-1", {} as any);
        session.registerPermissionHandler(() => ({ kind: "approve-once" }));
        const spy = vi
            .spyOn(session.rpc.permissions, "handlePendingPermissionRequest")
            .mockResolvedValue({ kind: "approve-once" } as any);

        await (session as any)._executePermissionAndRespond("request-1", { kind: "write" });

        expect(spy).toHaveBeenCalledOnce();
        const params = spy.mock.calls[0][0] as any;
        expect(params).toEqual({ requestId: "request-1", result: { kind: "approve-once" } });
        expect(Object.keys(params).sort()).toEqual(["requestId", "result"]);
        expect("decisionContext" in params).toBe(false);
    });

    it("does not respond when a no-result decision is wrapped with a context", async () => {
        const session = new CopilotSession("session-1", {} as any);
        const decisionContext = {
            outcome: "auto_approved" as const,
            source: "host_policy" as const,
            surface: "sdk" as const,
        };
        session.registerPermissionHandler(() =>
            createAttributedPermissionResult({ kind: "no-result" }, decisionContext)
        );
        const spy = vi.spyOn(session.rpc.permissions, "handlePendingPermissionRequest");

        await (session as any)._executePermissionAndRespond("request-1", { kind: "write" });

        expect(spy).not.toHaveBeenCalled();
    });

    it("replaces the context when applied twice", () => {
        const first = {
            outcome: "auto_approved" as const,
            source: "judge_recommendation" as const,
            surface: "sdk" as const,
        };
        const second = {
            outcome: "prompted_user" as const,
            source: "human_response" as const,
            surface: "tui" as const,
        };

        const once = createAttributedPermissionResult({ kind: "approve-once" }, first);
        const twice = createAttributedPermissionResult(once, second);

        expect(twice).toEqual({
            kind: "attributed",
            result: { kind: "approve-once" },
            decisionContext: second,
        });
        // The result stays unwrapped rather than nesting an AttributedPermissionResult.
        expect((twice.result as any).result).toBeUndefined();
        expect((twice.result as any).decisionContext).toBeUndefined();
    });

    it("responds to MCP OAuth requests with host token data", async () => {
        const sendRequest = vi.fn(async () => ({ success: true }));
        let observedRequest: any;
        const session = new CopilotSession(
            "session-1",
            { sendRequest } as any,
            undefined,
            undefined,
            {
                mcpAuthHandler: async (request) => {
                    observedRequest = request;
                    return {
                        accessToken: "host-token",
                        tokenType: "Bearer",
                        expiresIn: 3600,
                    };
                },
            }
        );

        await (session as any)._executeMcpAuthAndRespond({
            requestId: "oauth-request",
            serverName: "oauth-server",
            serverUrl: "https://example.com/mcp",
            reason: "initial",
            wwwAuthenticateParams: {
                resourceMetadataUrl: "https://example.com/.well-known/oauth-protected-resource",
            },
            resourceMetadata: '{"resource":"https://example.com/mcp"}',
            staticClientConfig: {
                clientId: "static-client",
                clientSecret: "static-secret",
                grantType: "client_credentials",
                publicClient: false,
                scope: "configured.read",
            },
        });

        expect(observedRequest.resourceMetadata).toBe('{"resource":"https://example.com/mcp"}');
        expect(observedRequest.staticClientConfig).toEqual({
            clientId: "static-client",
            clientSecret: "static-secret",
            grantType: "client_credentials",
            publicClient: false,
            scope: "configured.read",
        });
        expect(sendRequest).toHaveBeenCalledWith("session.mcp.oauth.handlePendingRequest", {
            sessionId: "session-1",
            requestId: "oauth-request",
            result: {
                kind: "token",
                accessToken: "host-token",
                tokenType: "Bearer",
                expiresIn: 3600,
            },
        });
    });

    it("forwards GitHub MCP tool config on create and resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        const githubMcpToolConfig = {
            enableAllTools: true,
            additionalToolsets: ["repos"],
            additionalTools: ["get_issue"],
            enableInsidersMode: true,
            disableFormDeferral: true,
        };

        const session = await client.createSession({ githubMcpToolConfig });
        await client.resumeSession(session.sessionId, { githubMcpToolConfig });

        expect(spy.mock.calls.find(([method]) => method === "session.create")![1]).toMatchObject({
            githubMcpToolConfig,
        });
        expect(spy.mock.calls.find(([method]) => method === "session.resume")![1]).toMatchObject({
            githubMcpToolConfig,
        });
    });

    it("forwards the ask-user variant on create and cold resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        const onElicitationRequest = async () => ({ action: "decline" as const });

        const session = await client.createSession({
            askUserVariant: "elicitation",
            onElicitationRequest,
        });
        await client.resumeSession(session.sessionId, {
            askUserVariant: "elicitation",
            onElicitationRequest,
        });

        expect(spy.mock.calls.find(([method]) => method === "session.create")![1]).toMatchObject({
            askUserVariant: "elicitation",
            requestElicitation: true,
        });
        expect(spy.mock.calls.find(([method]) => method === "session.resume")![1]).toMatchObject({
            askUserVariant: "elicitation",
            requestElicitation: true,
        });
    });

    it("omits GitHub MCP tool config when unset", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({});

        expect(
            spy.mock.calls.find(([method]) => method === "session.create")![1]
        ).not.toHaveProperty("githubMcpToolConfig");
    });

    it("passes MCP OAuth requests through when optional metadata is absent", async () => {
        let observedRequest: any;
        const session = new CopilotSession(
            "session-1",
            { sendRequest: vi.fn(async () => ({ success: true })) } as any,
            undefined,
            undefined,
            {
                mcpAuthHandler: async (request) => {
                    observedRequest = request;
                    return { kind: "cancelled" };
                },
            }
        );

        await (session as any)._executeMcpAuthAndRespond({
            requestId: "oauth-request",
            serverName: "oauth-server",
            serverUrl: "https://example.com/mcp",
            reason: "initial",
        });

        expect(observedRequest.reason).toBe("initial");
        expect(observedRequest.resourceMetadata).toBeUndefined();
        expect(observedRequest.wwwAuthenticateParams).toBeUndefined();
    });

    it("registers interest in MCP OAuth required events after create when an auth handler is configured", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.eventLog.registerInterest") {
                    return { id: "interest-1" };
                }
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            onMcpAuthRequest: () => ({ kind: "cancelled" }),
        });

        expect(spy.mock.calls[0][0]).toBe("session.create");
        expect(spy.mock.calls[1]).toEqual([
            "session.eventLog.registerInterest",
            expect.objectContaining({ eventType: "mcp.oauth_required" }),
        ]);
        expect(spy.mock.calls[1][1].sessionId).toBe(spy.mock.calls[0][1].sessionId);
    });

    it("does not register MCP OAuth interest without an auth handler", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            onEvent: () => {},
        });

        expect(spy).not.toHaveBeenCalledWith(
            "session.eventLog.registerInterest",
            expect.objectContaining({ eventType: "mcp.oauth_required" })
        );
        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({ requestPermission: true })
        );
    });

    it("forwards additional directories when creating and resuming sessions", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create" || method === "session.resume") {
                    return { sessionId: params.sessionId, workspacePath: "/workspace" };
                }
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            sessionId: "create-with-additional-directories",
            additionalDirectories: ["/repo/shared", "/repo/generated"],
            onPermissionRequest: approveAll,
        });
        await client.resumeSession("resume-with-additional-directories", {
            additionalDirectories: ["/repo/resumed"],
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({
                additionalDirectories: ["/repo/shared", "/repo/generated"],
            })
        );
        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({ additionalDirectories: ["/repo/resumed"] })
        );
    });

    it("registers MCP OAuth interest after cloud create only when an auth handler is configured", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        let cloudCreateCount = 0;
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, _params: any) => {
                if (method === "session.eventLog.registerInterest") {
                    return { id: "interest-1" };
                }
                if (method === "session.create")
                    return { sessionId: `server-assigned-session-${++cloudCreateCount}` };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            cloud: { repository: { owner: "github", name: "copilot-sdk", branch: "main" } },
        });

        expect(spy).not.toHaveBeenCalledWith(
            "session.eventLog.registerInterest",
            expect.objectContaining({ eventType: "mcp.oauth_required" })
        );

        spy.mockClear();
        await client.createSession({
            onPermissionRequest: approveAll,
            onMcpAuthRequest: () => ({ kind: "cancelled" }),
            cloud: { repository: { owner: "github", name: "copilot-sdk", branch: "main" } },
        });

        expect(spy.mock.calls[0][0]).toBe("session.create");
        expect(spy.mock.calls[1]).toEqual([
            "session.eventLog.registerInterest",
            { sessionId: "server-assigned-session-2", eventType: "mcp.oauth_required" },
        ]);
    });

    it("registers MCP OAuth interest after resuming only when an auth handler is configured", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.eventLog.registerInterest") {
                    return { id: "interest-1" };
                }
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSession("session-with-auth", {
            onPermissionRequest: approveAll,
            onMcpAuthRequest: () => ({ kind: "cancelled" }),
        });

        // `session.eventLog.registerInterest` is session-scoped: the runtime only
        // registers the session id while handling `session.resume`, so resume must
        // be sent BEFORE registering interest.
        const resumeIndex = spy.mock.calls.findIndex(([method]) => method === "session.resume");
        const interestIndex = spy.mock.calls.findIndex(
            ([method]) => method === "session.eventLog.registerInterest"
        );
        expect(resumeIndex).toBeGreaterThanOrEqual(0);
        expect(interestIndex).toBeGreaterThanOrEqual(0);
        expect(resumeIndex).toBeLessThan(interestIndex);
        expect(spy.mock.calls[resumeIndex][1]).toEqual(
            expect.objectContaining({ sessionId: "session-with-auth", requestPermission: true })
        );
        expect(spy.mock.calls[interestIndex][1]).toEqual({
            sessionId: "session-with-auth",
            eventType: "mcp.oauth_required",
        });

        spy.mockClear();
        await client.resumeSession("session-without-auth", {
            onPermissionRequest: approveAll,
            onEvent: () => {},
        });

        expect(spy).not.toHaveBeenCalledWith(
            "session.eventLog.registerInterest",
            expect.objectContaining({ eventType: "mcp.oauth_required" })
        );
        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({ sessionId: "session-without-auth", requestPermission: true })
        );
    });

    it("forwards canvas declarations and request flags in session.create", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const canvas = createCanvas({
            id: "counter",
            displayName: "Counter",
            description: "A counter canvas",
            actions: [{ name: "increment", description: "Increment the counter" }],
            open: () => ({ url: "https://example.test/counter" }),
        });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create")
                    return { sessionId: params.sessionId ?? "session-id" };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            canvases: [canvas],
            requestCanvasRenderer: true,
            requestExtensions: true,
            extensionInfo: { source: "github-app", name: "counter-provider" },
            canvasProvider: { id: "app:builtin:window-1", name: "Built-in" },
        });

        const payload = spy.mock.calls.find(([method]) => method === "session.create")![1] as any;
        expect(payload.canvases).toEqual([
            expect.objectContaining({
                id: "counter",
                displayName: "Counter",
                description: "A counter canvas",
                actions: [{ name: "increment", description: "Increment the counter" }],
            }),
        ]);
        expect(payload.requestCanvasRenderer).toBe(true);
        expect(payload.requestExtensions).toBe(true);
        expect(payload.extensionInfo).toEqual({
            source: "github-app",
            name: "counter-provider",
        });
        expect(payload.canvasProvider).toEqual({
            id: "app:builtin:window-1",
            name: "Built-in",
        });
    });

    it("forwards canvas declarations in session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const canvas = createCanvas({
            id: "counter",
            displayName: "Counter",
            description: "A counter canvas",
            open: () => ({ url: "https://example.test/counter" }),
        });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            canvases: [canvas],
            requestCanvasRenderer: true,
            requestExtensions: true,
            extensionInfo: { source: "github-app", name: "counter-provider" },
            canvasProvider: { id: "app:builtin:window-1" },
        });

        const payload = spy.mock.calls.find(([method]) => method === "session.resume")![1] as any;
        expect(payload.canvases).toEqual([expect.objectContaining({ id: "counter" })]);
        expect(payload.requestCanvasRenderer).toBe(true);
        expect(payload.requestExtensions).toBe(true);
        expect(payload.extensionInfo).toEqual({
            source: "github-app",
            name: "counter-provider",
        });
        expect(payload.canvasProvider).toEqual({ id: "app:builtin:window-1" });
        expect(payload.openCanvasInstances).toBeUndefined();
    });

    it("forwards an extension environment request and applies the grant to process.env", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));
        onTestFinished(() => {
            delete process.env.SDK_TEST_GRANTED_TOKEN;
        });

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") {
                    return {
                        sessionId: params.sessionId,
                        grantedEnvironmentVariables: { SDK_TEST_GRANTED_TOKEN: "granted-value" },
                    };
                }
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSessionForExtension(
            "session-env",
            { onPermissionRequest: defaultJoinSessionPermissionHandler },
            undefined,
            { requestedEnvironmentVariables: ["SDK_TEST_GRANTED_TOKEN"] }
        );

        const payload = spy.mock.calls.find(([method]) => method === "session.resume")![1] as any;
        expect(payload.requestedEnvironmentVariables).toEqual(["SDK_TEST_GRANTED_TOKEN"]);
        expect(process.env.SDK_TEST_GRANTED_TOKEN).toBe("granted-value");
    });

    it("ignores granted variables the extension never requested", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));
        onTestFinished(() => {
            delete process.env.SDK_TEST_GRANTED_TOKEN;
        });

        vi.spyOn((client as any).connection!, "sendRequest").mockImplementation(
            async (method: string, params: any) => {
                if (method === "session.resume") {
                    return {
                        sessionId: params.sessionId,
                        grantedEnvironmentVariables: {
                            SDK_TEST_GRANTED_TOKEN: "granted-value",
                            SDK_TEST_SMUGGLED: "not-approved",
                        },
                    };
                }
                throw new Error(`Unexpected method: ${method}`);
            }
        );

        await client.resumeSessionForExtension(
            "session-env-extra",
            { onPermissionRequest: defaultJoinSessionPermissionHandler },
            undefined,
            { requestedEnvironmentVariables: ["SDK_TEST_GRANTED_TOKEN"] }
        );

        expect(process.env.SDK_TEST_GRANTED_TOKEN).toBe("granted-value");
        // The user approved one name, so a host answering with a second one
        // cannot widen the grant.
        expect(process.env.SDK_TEST_SMUGGLED).toBeUndefined();
    });

    it("omits the environment request when a resume does not ask for one", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") {
                    return {
                        sessionId: params.sessionId,
                        grantedEnvironmentVariables: { SDK_TEST_UNREQUESTED: "leaked" },
                    };
                }
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSession("session-no-env", { onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find(([method]) => method === "session.resume")![1] as any;
        expect(payload).not.toHaveProperty("requestedEnvironmentVariables");
        // A grant is only honored for a request this client actually made.
        expect(process.env.SDK_TEST_UNREQUESTED).toBeUndefined();
    });

    it("forwards reasoningSummary in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            reasoningSummary: "concise",
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            reasoningSummary: "none",
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.reasoningSummary).toBe("concise");
        expect(resumePayload.reasoningSummary).toBe("none");
    });

    it("forwards enableExperimentalMode in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => client.forceStop());

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            enableExperimentalMode: false,
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            enableExperimentalMode: true,
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.isExperimentalMode).toBe(false);
        expect(resumePayload.isExperimentalMode).toBe(true);
    });

    it("defaults enableExperimentalMode by client mode", async () => {
        const baseDirectory = mkdtempSync(join(tmpdir(), "copilot-sdk-node-empty-"));
        const emptyClient = new CopilotClient({ mode: "empty", baseDirectory });
        await emptyClient.start();
        onTestFinished(() => emptyClient.forceStop());

        const emptySpy = vi
            .spyOn((emptyClient as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });

        const emptySession = await emptyClient.createSession({
            onPermissionRequest: approveAll,
            availableTools: [],
        });
        await emptyClient.resumeSession(emptySession.sessionId, {
            onPermissionRequest: approveAll,
            availableTools: [],
        });

        const emptyCreatePayload = emptySpy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const emptyResumePayload = emptySpy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(emptyCreatePayload.isExperimentalMode).toBe(false);
        expect(emptyResumePayload.isExperimentalMode).toBe(false);

        const cliClient = new CopilotClient();
        await cliClient.start();
        onTestFinished(() => cliClient.forceStop());

        const cliSpy = vi
            .spyOn((cliClient as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const cliSession = await cliClient.createSession({
            onPermissionRequest: approveAll,
        });
        await cliClient.resumeSession(cliSession.sessionId, {
            onPermissionRequest: approveAll,
        });

        const cliCreatePayload = cliSpy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const cliResumePayload = cliSpy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(cliCreatePayload.isExperimentalMode).toBeUndefined();
        expect(cliResumePayload.isExperimentalMode).toBeUndefined();
    });

    it.each(["empty", "copilot-cli"] as const)(
        "preserves transcript recovery overrides in %s mode and exposes the resume report",
        async (mode) => {
            const baseDirectory = mkdtempSync(join(tmpdir(), "copilot-sdk-node-recovery-"));
            const client = new CopilotClient({ mode, baseDirectory });
            await client.start();
            onTestFinished(() => client.forceStop());

            const recovery = {
                plannedBackupPath: "events.jsonl.backup",
                invalidLineNumbers: [2],
                sessionStartMoved: false,
            };
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string, params: any) => {
                    if (method === "session.create") return { sessionId: params.sessionId };
                    if (method === "session.resume") {
                        return { sessionId: params.sessionId, transcriptRecovery: recovery };
                    }
                    if (method === "session.options.update") return {};
                    throw new Error(`Unexpected method: ${method}`);
                });

            const created = await client.createSession({
                onPermissionRequest: approveAll,
                availableTools: [],
            });
            for (const setting of [undefined, false, true]) {
                const resumed = await client.resumeSession(created.sessionId, {
                    onPermissionRequest: approveAll,
                    availableTools: [],
                    allowTranscriptRecovery: setting,
                });
                expect(resumed.transcriptRecovery).toEqual(recovery);
                expect(
                    spy.mock.calls.filter(([method]) => method === "session.resume").at(-1)?.[1]
                ).toMatchObject({ allowTranscriptRecovery: setting });
            }
        }
    );

    it("forwards contextTier in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            contextTier: "long_context",
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            contextTier: "default",
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.contextTier).toBe("long_context");
        expect(resumePayload.contextTier).toBe("default");
    });

    it("forwards tool metadata verbatim in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => client.forceStop());

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const metadata = {
            "github.com/copilot:safeForTelemetry": { name: true, inputsNames: false },
        };
        const tool = {
            name: "my_tool",
            description: "a tool",
            parameters: { type: "object", properties: {} },
            metadata,
        };

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            tools: [tool],
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            tools: [tool],
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.tools[0].metadata).toEqual(metadata);
        expect(resumePayload.tools[0].metadata).toEqual(metadata);
    });

    it("omits tool metadata from session.create when unset", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => client.forceStop());

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            tools: [{ name: "my_tool", description: "a tool" }],
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        expect(createPayload.tools[0].metadata).toBeUndefined();
    });

    it("forwards tool isTerminal in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => client.forceStop());

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const tool = {
            name: "clear_context",
            description: "Clears the conversation",
            parameters: { type: "object", properties: {} },
            isTerminal: true,
        };

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            tools: [tool],
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            tools: [tool],
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.tools[0].isTerminal).toBe(true);
        expect(resumePayload.tools[0].isTerminal).toBe(true);
    });

    it("omits tool isTerminal from session.create when unset", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => client.forceStop());

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            tools: [{ name: "my_tool", description: "a tool" }],
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        expect(createPayload.tools[0].isTerminal).toBeUndefined();
    });

    it("forwards new session options in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            enableCitations: true,
            enableFileChangeTracking: true,
            excludedBuiltinAgents: ["explore"],
            sessionLimits: { maxAiCredits: 30 },
            diagnostics: { sources: { mcp: { level: "debug" } } },
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            enableCitations: false,
            enableFileChangeTracking: false,
            excludedBuiltinAgents: ["task"],
            sessionLimits: { maxAiCredits: 15 },
            diagnostics: { sources: { mcp: { level: "trace" } } },
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.enableCitations).toBe(true);
        expect(createPayload.enableFileChangeTracking).toBe(true);
        expect(createPayload.excludedBuiltinAgents).toEqual(["explore"]);
        expect(createPayload.sessionLimits).toEqual({ maxAiCredits: 30 });
        expect(createPayload.diagnostics).toEqual({ sources: { mcp: { level: "debug" } } });
        expect(resumePayload.enableCitations).toBe(false);
        expect(resumePayload.enableFileChangeTracking).toBe(false);
        expect(resumePayload.excludedBuiltinAgents).toEqual(["task"]);
        expect(resumePayload.sessionLimits).toEqual({ maxAiCredits: 15 });
        expect(resumePayload.diagnostics).toEqual({ sources: { mcp: { level: "trace" } } });
    });

    it("omits diagnostics when they are not configured", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create" || method === "session.resume") {
                    return { sessionId: params.sessionId };
                }
                throw new Error(`Unexpected method: ${method}`);
            });

        const session = await client.createSession({ onPermissionRequest: approveAll });
        await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as Record<string, unknown>;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as Record<string, unknown>;
        expect(createPayload).not.toHaveProperty("diagnostics");
        expect(resumePayload).not.toHaveProperty("diagnostics");
    });

    it("opts into GitHub telemetry forwarding when onGitHubTelemetry is provided", async () => {
        const client = new CopilotClient({ onGitHubTelemetry: () => {} });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const session = await client.createSession({ onPermissionRequest: approveAll });
        await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.enableGitHubTelemetryForwarding).toBe(true);
        expect(resumePayload.enableGitHubTelemetryForwarding).toBe(true);
    });

    it("opts into GitHub telemetry forwarding on the connect handshake when a handler is provided", async () => {
        const client = new CopilotClient({ onGitHubTelemetry: () => {} });
        onTestFinished(() => stopClient(client));

        const sendRequest = vi.fn(async (method: string) => {
            if (method === "connect") return { ok: true, protocolVersion: 3, version: "test" };
            throw new Error(`Unexpected method: ${method}`);
        });
        (client as any).connection = { sendRequest };

        await (client as any).verifyProtocolVersion();

        const connectCall = sendRequest.mock.calls.find(([method]) => method === "connect");
        expect(connectCall).toBeDefined();
        expect((connectCall![1] as any).enableGitHubTelemetryForwarding).toBe(true);
    });

    it("does not opt into GitHub telemetry forwarding on the connect handshake without a handler", async () => {
        const client = new CopilotClient();
        onTestFinished(() => stopClient(client));

        const sendRequest = vi.fn(async (method: string) => {
            if (method === "connect") return { ok: true, protocolVersion: 3, version: "test" };
            throw new Error(`Unexpected method: ${method}`);
        });
        (client as any).connection = { sendRequest };

        await (client as any).verifyProtocolVersion();

        const connectCall = sendRequest.mock.calls.find(([method]) => method === "connect");
        expect(connectCall).toBeDefined();
        expect((connectCall![1] as any).enableGitHubTelemetryForwarding).toBeUndefined();
    });

    it("does not opt into GitHub telemetry forwarding without a handler", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({ onPermissionRequest: approveAll });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        expect(createPayload.enableGitHubTelemetryForwarding).toBeUndefined();
    });

    it("dispatches a real gitHubTelemetry.event wire message to the handler", async () => {
        const { createMessageConnection, StreamMessageReader, StreamMessageWriter } =
            await import("vscode-jsonrpc/node.js");
        const { registerClientGlobalApiHandlers } = await import("../src/generated/rpc.js");

        const clientToServer = new PassThrough();
        const serverToClient = new PassThrough();

        const clientConn = createMessageConnection(
            new StreamMessageReader(serverToClient),
            new StreamMessageWriter(clientToServer)
        );
        const serverConn = createMessageConnection(
            new StreamMessageReader(clientToServer),
            new StreamMessageWriter(serverToClient)
        );
        onTestFinished(() => {
            clientConn.dispose();
            serverConn.dispose();
        });

        const received: GitHubTelemetryNotification[] = [];
        let resolveReceived: () => void;
        const got = new Promise<void>((resolve) => {
            resolveReceived = resolve;
        });

        registerClientGlobalApiHandlers(clientConn, {
            gitHubTelemetry: {
                event: async (notification) => {
                    received.push(notification);
                    resolveReceived();
                },
            },
        });

        clientConn.listen();
        serverConn.listen();

        const notification: GitHubTelemetryNotification = {
            sessionId: "session-1",
            restricted: false,
            event: {
                kind: "tool_call_executed",
                properties: { tool: "shell" },
                metrics: { duration_ms: 42 },
            },
        };

        // Deliver the event as a real JSON-RPC *notification* (no id) and confirm
        // the generated dispatcher routes it to the registered handler. The runtime
        // forwards telemetry via `sendNotification`, which only fires `onNotification`
        // handlers — an `onRequest` registration would never be invoked, so sending a
        // notification here guards against regressing back to request-style dispatch.
        serverConn.sendNotification("gitHubTelemetry.event", notification);
        await got;

        expect(received).toEqual([notification]);
    });

    it("registers no gitHubTelemetry handler when onGitHubTelemetry is omitted", () => {
        const client = new CopilotClient();
        onTestFinished(() => stopClient(client));

        const handlers = (client as any).clientGlobalHandlers;
        expect(handlers.gitHubTelemetry).toBeUndefined();
    });

    it("forwards gitHubTelemetry events to the onGitHubTelemetry handler", () => {
        const received: GitHubTelemetryNotification[] = [];
        const client = new CopilotClient({ onGitHubTelemetry: (n) => received.push(n) });
        onTestFinished(() => stopClient(client));

        const handlers = (client as any).clientGlobalHandlers;
        expect(handlers.gitHubTelemetry).toBeDefined();

        const notification: GitHubTelemetryNotification = {
            sessionId: "session-1",
            restricted: false,
            event: { kind: "tool_call_executed", properties: {}, metrics: {} },
        };
        handlers.gitHubTelemetry.event(notification);
        expect(received).toEqual([notification]);
    });

    it("forwards expAssignments in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const assignments = {
            Features: ["copilot_exp_flag"],
            Flights: { copilot_exp_flag: "treatment" },
            Configs: [{ Id: "cfg-1", Parameters: { threshold: 5, enabled: true } }],
            AssignmentContext: "ctx-123",
        };

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            expAssignments: assignments,
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            expAssignments: assignments,
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.expAssignments).toEqual(assignments);
        expect(resumePayload.expAssignments).toEqual(assignments);
    });

    it("omits expAssignments from session.create and session.resume when unset", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const session = await client.createSession({ onPermissionRequest: approveAll });
        await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.expAssignments).toBeUndefined();
        expect(resumePayload.expAssignments).toBeUndefined();
    });

    it("forwards featureFlags in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        const featureFlags = { ENABLED_TEST_FLAG: true, DISABLED_TEST_FLAG: false };

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            featureFlags,
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            featureFlags,
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.featureFlags).toEqual(featureFlags);
        expect(resumePayload.featureFlags).toEqual(featureFlags);
    });

    it.each([
        undefined,
        {},
        { enableWebSocketResponses: false },
        { enableWebSocketResponses: true },
        { autoTier: "efficiency" },
        { autoTier: "balance" },
        { autoTier: "intelligence" },
        { autoTier: "fast" },
        { autoTier: "balance", enableWebSocketResponses: false },
    ] satisfies (CapiSessionOptions | undefined)[])(
        "forwards capi options %j in session.create and session.resume",
        async (capi) => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string, params: any) => {
                    if (method === "session.create") return { sessionId: params.sessionId };
                    if (method === "session.resume") return { sessionId: params.sessionId };
                    throw new Error(`Unexpected method: ${method}`);
                });

            const session = await client.createSession({
                onPermissionRequest: approveAll,
                model: "auto",
                capi,
            });
            await client.resumeSession(session.sessionId, {
                onPermissionRequest: approveAll,
                capi,
            });

            const createPayload = spy.mock.calls.find(
                ([method]) => method === "session.create"
            )![1] as any;
            const resumePayload = spy.mock.calls.find(
                ([method]) => method === "session.resume"
            )![1] as any;
            expect(JSON.parse(JSON.stringify(createPayload)).capi).toEqual(capi);
            expect(JSON.parse(JSON.stringify(resumePayload)).capi).toEqual(capi);
        }
    );

    it("forwards pluginDirectories and largeOutput in session.create and session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        const pluginDirs = ["/tmp/plugins/a", "/tmp/plugins/b"];
        const disabledMcpServers = ["local-files", "remote-github"];
        const largeOutput = {
            enabled: true,
            maxSizeBytes: 1024,
            outputDirectory: "/tmp/large-output",
        };
        const expectedWireLargeOutput = {
            enabled: true,
            maxSizeBytes: 1024,
            outputDir: "/tmp/large-output",
        };

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            pluginDirectories: pluginDirs,
            disabledMcpServers,
            largeOutput,
        });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            pluginDirectories: pluginDirs,
            disabledMcpServers,
            largeOutput,
        });

        const createPayload = spy.mock.calls.find(
            ([method]) => method === "session.create"
        )![1] as any;
        const resumePayload = spy.mock.calls.find(
            ([method]) => method === "session.resume"
        )![1] as any;
        expect(createPayload.pluginDirectories).toEqual(pluginDirs);
        expect(createPayload.disabledMcpServers).toEqual(disabledMcpServers);
        expect(createPayload.largeOutput).toEqual(expectedWireLargeOutput);
        expect(resumePayload.pluginDirectories).toEqual(pluginDirs);
        expect(resumePayload.disabledMcpServers).toEqual(disabledMcpServers);
        expect(resumePayload.largeOutput).toEqual(expectedWireLargeOutput);
    });

    it("routes canvas.action.invoke to registered canvas action handlers via clientSessionApis", async () => {
        const canvas = createCanvas({
            id: "counter",
            displayName: "Counter",
            description: "A counter canvas",
            open: ({ instanceId }) => ({ url: `https://example.test/${instanceId}` }),
            actions: [
                {
                    name: "increment",
                    handler: ({ actionName, input }) => ({ actionName, input }),
                },
            ],
        });
        const session = new CopilotSession("session-1", {} as any);
        session.registerCanvases([canvas]);

        const result = await session.clientSessionApis.canvas!.invoke({
            sessionId: session.sessionId,
            extensionId: "project:counter",
            canvasId: "counter",
            instanceId: "counter-1",
            actionName: "increment",
            input: { amount: 1 },
        });

        expect(result).toEqual({ actionName: "increment", input: { amount: 1 } });
    });

    it("tracks open canvases from live session.canvas.opened events", () => {
        const session = new CopilotSession("session-1", {} as any);
        const warn = vi.spyOn(console, "warn").mockImplementation(() => {});

        (session as any)._dispatchEvent({
            type: "session.canvas.opened",
            data: { instanceId: "missing-required-fields" },
        });
        (session as any)._dispatchEvent({
            type: "session.canvas.opened",
            data: {
                extensionId: "project:counter",
                extensionName: "Counter Provider",
                canvasId: "counter",
                instanceId: "counter-1",
                title: "Counter",
                status: "ready",
                url: "https://example.test/counter",
                input: { seed: 1 },
            },
        });
        (session as any)._dispatchEvent({
            type: "session.canvas.opened",
            data: {
                extensionId: "project:logs",
                canvasId: "logs",
                instanceId: "logs-1",
                title: "Logs",
            },
        });

        expect(warn).toHaveBeenCalledWith("failed to deserialize session.canvas.opened payload");
        expect(session.openCanvases.map((canvas) => canvas.instanceId)).toEqual([
            "counter-1",
            "logs-1",
        ]);

        (session as any)._dispatchEvent({
            type: "session.canvas.opened",
            data: {
                extensionId: "project:counter",
                extensionName: "Counter Provider",
                canvasId: "counter",
                instanceId: "counter-1",
                title: "Counter Updated",
                status: "reconnected",
                url: "https://example.test/counter-updated",
                input: { seed: 2 },
            },
        });

        expect(session.openCanvases).toHaveLength(2);
        expect(session.openCanvases[0]).toMatchObject({
            instanceId: "counter-1",
            title: "Counter Updated",
            status: "reconnected",
            url: "https://example.test/counter-updated",
            input: { seed: 2 },
        });
        expect(session.openCanvases[1].instanceId).toBe("logs-1");
        warn.mockRestore();
    });

    it("removes open canvases on live session.canvas.closed events", () => {
        const session = new CopilotSession("session-1", {} as any);
        const warn = vi.spyOn(console, "warn").mockImplementation(() => {});

        (session as any)._dispatchEvent({
            type: "session.canvas.opened",
            data: {
                extensionId: "project:counter",
                canvasId: "counter",
                instanceId: "counter-1",
                title: "Counter",
            },
        });
        (session as any)._dispatchEvent({
            type: "session.canvas.opened",
            data: {
                extensionId: "project:logs",
                canvasId: "logs",
                instanceId: "logs-1",
                title: "Logs",
            },
        });
        expect(session.openCanvases.map((canvas) => canvas.instanceId)).toEqual([
            "counter-1",
            "logs-1",
        ]);

        // Closing one instance removes it; the other remains.
        (session as any)._dispatchEvent({
            type: "session.canvas.closed",
            data: {
                extensionId: "project:counter",
                canvasId: "counter",
                instanceId: "counter-1",
            },
        });
        expect(session.openCanvases.map((canvas) => canvas.instanceId)).toEqual(["logs-1"]);

        // Closing an absent instance is a no-op (idempotent).
        (session as any)._dispatchEvent({
            type: "session.canvas.closed",
            data: {
                extensionId: "project:counter",
                canvasId: "counter",
                instanceId: "counter-1",
            },
        });
        expect(session.openCanvases.map((canvas) => canvas.instanceId)).toEqual(["logs-1"]);

        // A closed event missing instanceId warns and leaves the snapshot intact.
        (session as any)._dispatchEvent({
            type: "session.canvas.closed",
            data: { extensionId: "project:logs", canvasId: "logs" },
        });
        expect(warn).toHaveBeenCalledWith("failed to deserialize session.canvas.closed payload");
        expect(session.openCanvases.map((canvas) => canvas.instanceId)).toEqual(["logs-1"]);
        warn.mockRestore();
    });

    it("returns canvas_action_no_handler when no per-action handler is registered", async () => {
        const canvas = createCanvas({
            id: "counter",
            displayName: "Counter",
            description: "A counter canvas",
            open: () => ({ url: "https://example.test/counter" }),
        });

        const session = new CopilotSession("session-1", {} as any);
        session.registerCanvases([canvas]);

        await expect(
            session.clientSessionApis.canvas!.invoke({
                sessionId: session.sessionId,
                extensionId: "project:counter",
                canvasId: "counter",
                instanceId: "counter-1",
                actionName: "ghost",
                input: undefined,
            })
        ).rejects.toMatchObject({ code: "canvas_action_no_handler" });
    });

    it("throws for unknown canvasId in canvas.open via clientSessionApis", async () => {
        const session = new CopilotSession("session-1", {} as any);
        const canvas = createCanvas({
            id: "other",
            displayName: "Other",
            description: "Some other canvas",
            open: () => ({ url: "https://example.test/other" }),
        });
        session.registerCanvases([canvas]);

        await expect(
            session.clientSessionApis.canvas!.open({
                sessionId: session.sessionId,
                extensionId: "project:missing",
                canvasId: "missing",
                instanceId: "missing-1",
            })
        ).rejects.toThrow('No canvas registered with id "missing"');
    });

    it("forwards clientName in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({ clientName: "my-app", onPermissionRequest: approveAll });

        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({ clientName: "my-app" })
        );
    });

    it("forwards cloud options in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockResolvedValue({ sessionId: "cloud-session" });
        await client.createSession({
            onPermissionRequest: approveAll,
            cloud: {
                repository: { owner: "github", name: "copilot-sdk", branch: "main" },
            },
        });

        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({
                cloud: {
                    repository: { owner: "github", name: "copilot-sdk", branch: "main" },
                },
            })
        );
    });

    it("deletes an uninitialized cloud session after binary provider validation fails", async () => {
        const client = new CopilotClient({
            sessionFs: {
                initialCwd: "/",
                sessionStatePath: "/state",
                conventions: "posix",
                capabilities: { binary: true },
            },
        });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string) => {
                if (method === "session.create") return { sessionId: "cloud-invalid-provider" };
                if (method === "session.delete") return { success: true };
                throw new Error(`Unexpected method: ${method}`);
            });
        try {
            await expect(
                client.createSession({
                    onPermissionRequest: approveAll,
                    cloud: { repository: { owner: "github", name: "copilot-sdk", branch: "main" } },
                    createSessionFsProvider: () => ({}) as SessionFsProvider,
                })
            ).rejects.toThrow("does not implement readFileBytes");
            expect(spy).toHaveBeenCalledWith("session.delete", {
                sessionId: "cloud-invalid-provider",
            });
            expect((client as any).sessions.has("cloud-invalid-provider")).toBe(false);
        } finally {
            spy.mockRestore();
        }
    });

    it("bounds cloud session cleanup when binary provider validation fails", async () => {
        const client = new CopilotClient({
            sessionFs: {
                initialCwd: "/",
                sessionStatePath: "/state",
                conventions: "posix",
                capabilities: { binary: true },
            },
        });
        await client.start();
        onTestFinished(() => stopClient(client));

        const deleteStarted = Promise.withResolvers<void>();
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string) => {
                if (method === "session.create") return { sessionId: "cloud-stalled-delete" };
                if (method === "session.delete") {
                    deleteStarted.resolve();
                    return new Promise<never>(() => {});
                }
                throw new Error(`Unexpected method: ${method}`);
            });
        vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout"] });
        try {
            const failure = client
                .createSession({
                    onPermissionRequest: approveAll,
                    cloud: { repository: { owner: "github", name: "copilot-sdk", branch: "main" } },
                    createSessionFsProvider: () => ({}) as SessionFsProvider,
                })
                .catch((error: unknown) => error);

            await deleteStarted.promise;
            await vi.advanceTimersByTimeAsync(10_000);

            const error = await failure;
            expect(error).toBeInstanceOf(AggregateError);
            if (!(error instanceof AggregateError)) throw error;
            expect(error.errors).toEqual([
                expect.objectContaining({
                    message: expect.stringContaining("does not implement readFileBytes"),
                }),
                expect.objectContaining({ message: "session.delete timed out after 10000ms" }),
            ]);
            expect((client as any).sessions.has("cloud-stalled-delete")).toBe(false);
        } finally {
            vi.useRealTimers();
            spy.mockRestore();
        }
    });

    it("does not register a session when binary provider validation fails during local create or resume", async () => {
        const client = new CopilotClient({
            sessionFs: {
                initialCwd: "/",
                sessionStatePath: "/state",
                conventions: "posix",
                capabilities: { binary: true },
            },
        });
        await client.start();
        onTestFinished(() => stopClient(client));

        const invalidProvider = () => ({}) as SessionFsProvider;
        await expect(
            client.createSession({
                onPermissionRequest: approveAll,
                createSessionFsProvider: invalidProvider,
            })
        ).rejects.toThrow("does not implement readFileBytes");
        await expect(
            client.resumeSession("missing-provider", {
                onPermissionRequest: approveAll,
                createSessionFsProvider: invalidProvider,
            })
        ).rejects.toThrow("does not implement readFileBytes");
        expect((client as any).sessions.size).toBe(0);
    });

    it("forwards clientName in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        // Mock sendRequest to capture the call without hitting the runtime
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, {
            clientName: "my-app",
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({ clientName: "my-app", sessionId: session.sessionId })
        );
        spy.mockRestore();
    });

    it("forwards enableSessionTelemetry in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({
            enableSessionTelemetry: false,
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({ enableSessionTelemetry: false })
        );
    });

    it("forwards enableSessionTelemetry in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, {
            enableSessionTelemetry: false,
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({ enableSessionTelemetry: false, sessionId: session.sessionId })
        );
        spy.mockRestore();
    });

    it.each([true, false, undefined])(
        "serializes refreshCustomInstructions=%s only on session.create",
        async (refresh) => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            const config = {
                onPermissionRequest: approveAll,
                refreshCustomInstructions: refresh,
            };
            const session = await client.createSession(config);
            const createRequest = spy.mock.calls.find(([method]) => method === "session.create");
            expect(createRequest).toBeDefined();
            const payload = JSON.parse(JSON.stringify(createRequest![1]));
            if (refresh === undefined) {
                expect(payload).not.toHaveProperty("refreshCustomInstructions");
            } else {
                expect(payload).toHaveProperty("refreshCustomInstructions", refresh);
            }

            await client.resumeSession(session.sessionId, config);
            const resumeRequest = spy.mock.calls.find(([method]) => method === "session.resume");
            expect(resumeRequest).toBeDefined();
            expect(JSON.parse(JSON.stringify(resumeRequest![1]))).not.toHaveProperty(
                "refreshCustomInstructions"
            );
        }
    );

    it("forwards enableOnDemandInstructionDiscovery in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({
            enableOnDemandInstructionDiscovery: false,
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({ enableOnDemandInstructionDiscovery: false })
        );
    });

    it("forwards enableOnDemandInstructionDiscovery in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, {
            enableOnDemandInstructionDiscovery: false,
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({
                enableOnDemandInstructionDiscovery: false,
                sessionId: session.sessionId,
            })
        );
        spy.mockRestore();
    });

    it("defaults includeSubAgentStreamingEvents to true in session.create when not specified", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({ onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.includeSubAgentStreamingEvents).toBe(true);
    });

    it("forwards explicit false for includeSubAgentStreamingEvents in session.create", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({
            onPermissionRequest: approveAll,
            includeSubAgentStreamingEvents: false,
        });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.includeSubAgentStreamingEvents).toBe(false);
    });

    it("defaults includeSubAgentStreamingEvents to true in session.resume when not specified", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.includeSubAgentStreamingEvents).toBe(true);
        spy.mockRestore();
    });

    it("forwards explicit false for includeSubAgentStreamingEvents in session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            includeSubAgentStreamingEvents: false,
        });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.includeSubAgentStreamingEvents).toBe(false);
        spy.mockRestore();
    });

    it("defaults mcpOAuthTokenStorage to 'in-memory' in session.create when mode is empty", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, availableTools: [] });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.mcpOAuthTokenStorage).toBe("in-memory");
    });

    it("does not send mcpOAuthTokenStorage in session.create when mode is copilot-cli", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({ onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.mcpOAuthTokenStorage).toBeUndefined();
    });

    it("forwards explicit 'persistent' for mcpOAuthTokenStorage in session.create", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({
            onPermissionRequest: approveAll,
            availableTools: [],
            mcpOAuthTokenStorage: "persistent",
        });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.mcpOAuthTokenStorage).toBe("persistent");
    });

    it("defaults mcpOAuthTokenStorage to 'in-memory' in session.resume when mode is empty", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.resume") return { sessionId: params.sessionId };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, availableTools: [] });
        await client.resumeSession("s1", { onPermissionRequest: approveAll, availableTools: [] });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.mcpOAuthTokenStorage).toBe("in-memory");
    });

    it("forwards explicit 'persistent' for mcpOAuthTokenStorage in session.resume", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.resume") return { sessionId: params.sessionId };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, availableTools: [] });
        await client.resumeSession("s1", {
            onPermissionRequest: approveAll,
            availableTools: [],
            mcpOAuthTokenStorage: "persistent",
        });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.mcpOAuthTokenStorage).toBe("persistent");
    });

    it("defaults memory to { enabled: false } in session.create when mode is empty", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, availableTools: [] });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.memory).toEqual({ enabled: false });
    });

    it("does not send memory in session.create when mode is copilot-cli", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({ onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.memory).toBeUndefined();
    });

    it("forwards explicit memory config in session.create even in empty mode", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({
            onPermissionRequest: approveAll,
            availableTools: [],
            memory: { enabled: true },
        });

        const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(payload.memory).toEqual({ enabled: true });
    });

    it("defaults memory to { enabled: false } in session.resume when mode is empty", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.resume") return { sessionId: params.sessionId };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, availableTools: [] });
        await client.resumeSession("s1", { onPermissionRequest: approveAll, availableTools: [] });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.memory).toEqual({ enabled: false });
    });

    it("does not send memory in session.resume when mode is copilot-cli", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.memory).toBeUndefined();
        spy.mockRestore();
    });

    it("sends includedBuiltinSkills=[] in the empty-mode post-create options patch", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, availableTools: [] });

        const patch = spy.mock.calls.find((c) => c[0] === "session.options.update")![1] as any;
        expect(patch.includedBuiltinSkills).toEqual([]);
        expect(patch.installedPlugins).toEqual([]);
    });

    it("sends includedBuiltinSkills=[] in the empty-mode post-resume options patch", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.resume") return { sessionId: params.sessionId };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, availableTools: [] });
        spy.mockClear();
        await client.resumeSession("s1", { onPermissionRequest: approveAll, availableTools: [] });

        const patch = spy.mock.calls.find((c) => c[0] === "session.options.update")![1] as any;
        expect(patch.includedBuiltinSkills).toEqual([]);
    });

    it("preserves an explicit built-in skill allowlist after empty-mode resume", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string) => {
                if (method === "session.resume") return { sessionId: "s1" };
                if (method === "session.options.update") return { success: true };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession("s1", {
            onPermissionRequest: approveAll,
            availableTools: [],
            includedBuiltinSkills: ["code-review"],
        });

        const patch = spy.mock.calls.find((c) => c[0] === "session.options.update")![1] as any;
        expect(patch.includedBuiltinSkills).toEqual(["code-review"]);
    });

    it("keeps includedBuiltinSkills=[] even when the caller opts into custom skills in empty mode", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId ?? "s1" };
                if (method === "session.options.update") return {};
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({
            onPermissionRequest: approveAll,
            availableTools: [],
            enableSkills: true,
            skillDirectories: ["/tmp/custom-skills"],
        });

        const createPayload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(createPayload.enableSkills).toBe(true);
        expect(createPayload.skillDirectories).toEqual(["/tmp/custom-skills"]);
        const patch = spy.mock.calls.find((c) => c[0] === "session.options.update")![1] as any;
        expect(patch.includedBuiltinSkills).toEqual([]);
    });

    it("preserves an explicit built-in skill allowlist in empty mode", async () => {
        const client = new CopilotClient({ mode: "empty", baseDirectory: "/tmp/copilot-test" });
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                if (method === "session.options.update") return { success: true };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({
            onPermissionRequest: approveAll,
            availableTools: [],
            includedBuiltinSkills: ["code-review"],
        });

        const patch = spy.mock.calls.find((c) => c[0] === "session.options.update")![1] as any;
        expect(patch.includedBuiltinSkills).toEqual(["code-review"]);
    });

    it("does not send includedBuiltinSkills in copilot-cli mode", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({ onPermissionRequest: approveAll });

        const patch = spy.mock.calls.find((c) => c[0] === "session.options.update");
        // copilot-cli mode sends no post-create options patch at all here.
        if (patch) {
            expect((patch[1] as any).includedBuiltinSkills).toBeUndefined();
        }
        const createPayload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
        expect(createPayload.includedBuiltinSkills).toBeUndefined();
        spy.mockRestore();
    });

    it("forwards continuePendingWork in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            continuePendingWork: true,
        });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.continuePendingWork).toBe(true);
        spy.mockRestore();
    });

    it("omits continuePendingWork from session.resume payload when not specified", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.continuePendingWork).toBeUndefined();
        spy.mockRestore();
    });

    it("forwards memory configuration in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create")
                    return { sessionId: params.sessionId ?? "session-id" };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            memory: { enabled: true },
        });

        const payload = spy.mock.calls.find(([method]) => method === "session.create")![1] as any;
        expect(payload.memory).toEqual({ enabled: true });
        spy.mockRestore();
    });

    it("forwards memory configuration in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            memory: { enabled: false },
        });

        const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
        expect(payload.memory).toEqual({ enabled: false });
        spy.mockRestore();
    });

    it("omits memory from session.create payload when not specified", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create")
                    return { sessionId: params.sessionId ?? "session-id" };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({ onPermissionRequest: approveAll });

        const payload = spy.mock.calls.find(([method]) => method === "session.create")![1] as any;
        const serialized = JSON.parse(JSON.stringify(payload));
        expect(serialized).not.toHaveProperty("memory");
        spy.mockRestore();
    });

    it("forwards provider headers in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create")
                    return { sessionId: params.sessionId ?? "session-id" };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            provider: {
                baseUrl: "https://example.com/provider",
                headers: { Authorization: "Bearer provider-token" },
                modelId: "gpt-4o",
                wireModel: "my-finetune-v3",
                modelProvider: "lm_studio",
                maxPromptTokens: 100_000,
                maxOutputTokens: 4096,
                transport: "websockets",
            },
        });

        const payload = spy.mock.calls.find(([method]) => method === "session.create")![1] as any;
        expect(payload.provider).toEqual(
            expect.objectContaining({
                baseUrl: "https://example.com/provider",
                headers: { Authorization: "Bearer provider-token" },
                modelId: "gpt-4o",
                wireModel: "my-finetune-v3",
                modelProvider: "lm_studio",
                maxPromptTokens: 100_000,
                maxOutputTokens: 4096,
                transport: "websockets",
            })
        );
        spy.mockRestore();
    });

    it("forwards provider headers in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            provider: {
                baseUrl: "https://example.com/provider",
                headers: { Authorization: "Bearer resume-token" },
                modelId: "gpt-4o",
                wireModel: "my-finetune-v3",
                modelProvider: "ollama",
                maxPromptTokens: 100_000,
                maxOutputTokens: 4096,
                transport: "websockets",
            },
        });

        const payload = spy.mock.calls.find(([method]) => method === "session.resume")![1] as any;
        expect(payload.provider).toEqual(
            expect.objectContaining({
                baseUrl: "https://example.com/provider",
                headers: { Authorization: "Bearer resume-token" },
                modelId: "gpt-4o",
                wireModel: "my-finetune-v3",
                modelProvider: "ollama",
                maxPromptTokens: 100_000,
                maxOutputTokens: 4096,
                transport: "websockets",
            })
        );
        spy.mockRestore();
    });

    it("forwards named provider model provider in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create")
                    return { sessionId: params.sessionId ?? "session-id" };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.createSession({
            onPermissionRequest: approveAll,
            providers: [
                {
                    name: "local",
                    baseUrl: "http://localhost:11434/v1",
                    type: "openai",
                    modelProvider: "ollama",
                },
            ],
            models: [{ id: "llama3", provider: "local" }],
        });

        const payload = spy.mock.calls.find(([method]) => method === "session.create")![1] as any;
        expect(payload.providers).toEqual([
            expect.objectContaining({
                name: "local",
                baseUrl: "http://localhost:11434/v1",
                type: "openai",
                modelProvider: "ollama",
            }),
        ]);
        spy.mockRestore();
    });

    it("forwards defaultAgent in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({
            defaultAgent: { excludedTools: ["heavy-tool"] },
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({
                defaultAgent: { excludedTools: ["heavy-tool"] },
            })
        );
    });

    it("forwards defaultAgent in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.resumeSession(session.sessionId, {
            defaultAgent: { excludedTools: ["heavy-tool"] },
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({
                defaultAgent: { excludedTools: ["heavy-tool"] },
            })
        );
    });

    it("forwards instructionDirectories in session.create request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const instructionDirectories = ["C:\\extra-instructions", "C:\\more-instructions"];
        const spy = vi.spyOn((client as any).connection!, "sendRequest");
        await client.createSession({
            instructionDirectories,
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.create",
            expect.objectContaining({ instructionDirectories })
        );
    });

    it("forwards instructionDirectories in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const instructionDirectories = ["C:\\resume-instructions"];
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession(session.sessionId, {
            instructionDirectories,
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({
                instructionDirectories,
                sessionId: session.sessionId,
            })
        );
        spy.mockRestore();
    });

    it("does not request permissions on session.resume when using the default joinSession handler", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSession(session.sessionId, {
            onPermissionRequest: defaultJoinSessionPermissionHandler,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({
                sessionId: session.sessionId,
                requestPermission: false,
            })
        );
        spy.mockRestore();
    });

    it("requests permissions on session.resume when using an explicit handler", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({
                sessionId: session.sessionId,
                requestPermission: true,
            })
        );
        spy.mockRestore();
    });

    it("forwards mode callback request flags in session.resume request", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });

        await client.resumeSession(session.sessionId, {
            onPermissionRequest: approveAll,
            onExitPlanModeRequest: () => ({ approved: true }),
            onAutoModeSwitchRequest: () => "yes",
        });

        expect(spy).toHaveBeenCalledWith(
            "session.resume",
            expect.objectContaining({
                sessionId: session.sessionId,
                requestExitPlanMode: true,
                requestAutoModeSwitch: true,
            })
        );
        spy.mockRestore();
    });

    it("sends session.model.switchTo RPC with correct params", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });

        // Mock sendRequest to capture the call without hitting the runtime
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, _params: any) => {
                if (method === "session.model.switchTo") return {};
                // Fall through for other methods (shouldn't be called)
                throw new Error(`Unexpected method: ${method}`);
            });

        await session.setModel("gpt-4.1");

        expect(spy).toHaveBeenCalledWith("session.model.switchTo", {
            sessionId: session.sessionId,
            modelId: "gpt-4.1",
        });

        spy.mockRestore();
    });

    it("sends reasoning options with session.model.switchTo when provided", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, _params: any) => {
                if (method === "session.model.switchTo") return {};
                throw new Error(`Unexpected method: ${method}`);
            });

        await session.setModel("claude-sonnet-4.6", {
            reasoningEffort: "high",
            reasoningSummary: "detailed",
            contextTier: "long_context",
        });

        expect(spy).toHaveBeenCalledWith("session.model.switchTo", {
            sessionId: session.sessionId,
            modelId: "claude-sonnet-4.6",
            reasoningEffort: "high",
            reasoningSummary: "detailed",
            contextTier: "long_context",
        });

        spy.mockRestore();
    });

    it("sends the auto tier with session.model.switchTo when selecting the auto model", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, _params: any) => {
                if (method === "session.model.switchTo") return {};
                throw new Error(`Unexpected method: ${method}`);
            });

        await session.setModel("auto", { autoTier: "fast" });

        expect(spy).toHaveBeenCalledWith("session.model.switchTo", {
            sessionId: session.sessionId,
            modelId: "auto",
            autoTier: "fast",
        });

        spy.mockRestore();
    });

    it("sends a null auto tier with session.model.switchTo to restore default routing", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, _params: any) => {
                if (method === "session.model.switchTo") return {};
                throw new Error(`Unexpected method: ${method}`);
            });

        await session.setModel("auto", { autoTier: null });

        expect(spy).toHaveBeenCalledWith("session.model.switchTo", {
            sessionId: session.sessionId,
            modelId: "auto",
            autoTier: null,
        });

        spy.mockRestore();
    });

    it("sends session.model.switchAutoTier RPC and returns the runtime snapshot", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, _params: any) => {
                if (method === "session.model.switchAutoTier") {
                    return {
                        status: "pending",
                        effectiveAutoTier: "balance",
                        pendingAutoTier: "fast",
                        activatingAutoTier: null,
                        supersededAutoTier: null,
                    };
                }
                throw new Error(`Unexpected method: ${method}`);
            });

        const result = await session.setAutoTier("fast");

        expect(spy).toHaveBeenCalledWith("session.model.switchAutoTier", {
            sessionId: session.sessionId,
            autoTier: "fast",
        });
        expect(result.status).toBe("pending");
        expect(result.effectiveAutoTier).toBe("balance");
        expect(result.pendingAutoTier).toBe("fast");
        expect(result.activatingAutoTier).toBeNull();

        spy.mockRestore();
    });

    it("sends a null auto tier with session.model.switchAutoTier to restore default routing", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));

        const session = await client.createSession({ onPermissionRequest: approveAll });

        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, _params: any) => {
                if (method === "session.model.switchAutoTier") return { status: "unchanged" };
                throw new Error(`Unexpected method: ${method}`);
            });

        const result = await session.setAutoTier(null);

        expect(spy).toHaveBeenCalledWith("session.model.switchAutoTier", {
            sessionId: session.sessionId,
            autoTier: null,
        });
        expect(result.status).toBe("unchanged");

        spy.mockRestore();
    });

    describe("URL parsing", () => {
        it("should parse port-only URL format", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("8080"),
                logLevel: "error",
            });

            expect((client as any).runtimePort).toBe(8080);
            expect((client as any).actualHost).toBe("localhost");
            expect((client as any).isExternalServer).toBe(true);
        });

        it("should parse host:port URL format", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("127.0.0.1:9000"),
                logLevel: "error",
            });

            expect((client as any).runtimePort).toBe(9000);
            expect((client as any).actualHost).toBe("127.0.0.1");
            expect((client as any).isExternalServer).toBe(true);
        });

        it("should parse bracketed IPv6 host:port URL format", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("[::1]:9000"),
                logLevel: "error",
            });

            expect((client as any).runtimePort).toBe(9000);
            expect((client as any).actualHost).toBe("::1");
            expect((client as any).isExternalServer).toBe(true);
        });

        it("should parse http://host:port URL format", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("http://localhost:7000"),
                logLevel: "error",
            });

            expect((client as any).runtimePort).toBe(7000);
            expect((client as any).actualHost).toBe("localhost");
            expect((client as any).isExternalServer).toBe(true);
        });

        it("should parse http://[ipv6]:port URL format", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("http://[::1]:7000"),
                logLevel: "error",
            });

            expect((client as any).runtimePort).toBe(7000);
            expect((client as any).actualHost).toBe("::1");
            expect((client as any).isExternalServer).toBe(true);
        });

        it("should reject a bracketed non-IPv6 host", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forUri("[not-ipv6]:1234"),
                    logLevel: "error",
                });
            }).toThrow(/Invalid cliUrl format/);
        });

        it("should parse https://host:port URL format", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("https://example.com:443"),
                logLevel: "error",
            });

            expect((client as any).runtimePort).toBe(443);
            expect((client as any).actualHost).toBe("example.com");
            expect((client as any).isExternalServer).toBe(true);
        });

        it("should throw error for invalid URL format", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forUri("invalid-url"),
                    logLevel: "error",
                });
            }).toThrow(/Invalid cliUrl format/);
        });

        it("should throw error for invalid port - too high", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forUri("localhost:99999"),
                    logLevel: "error",
                });
            }).toThrow(/Invalid port in cliUrl/);
        });

        it("should throw error for invalid port - zero", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forUri("localhost:0"),
                    logLevel: "error",
                });
            }).toThrow(/Invalid port in cliUrl/);
        });

        it("should throw error for invalid port - negative", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forUri("localhost:-1"),
                    logLevel: "error",
                });
            }).toThrow(/Invalid port in cliUrl/);
        });

        it("should mark client as using external server", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("localhost:8080"),
                logLevel: "error",
            });

            expect((client as any).isExternalServer).toBe(true);
        });

        it("should not resolve a CLI path when forUri is used", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forUri("localhost:8080"),
                logLevel: "error",
            });

            expect((client as any).resolvedCliPath).toBeUndefined();
        });
    });

    describe("SessionFs config", () => {
        it("throws when initialCwd is missing", () => {
            expect(() => {
                new CopilotClient({
                    sessionFs: {
                        initialCwd: "",
                        sessionStatePath: "/session-state",
                        conventions: "posix",
                    },
                    logLevel: "error",
                });
            }).toThrow(/sessionFs\.initialCwd is required/);
        });

        it("throws when sessionStatePath is missing", () => {
            expect(() => {
                new CopilotClient({
                    sessionFs: {
                        initialCwd: "/",
                        sessionStatePath: "",
                        conventions: "posix",
                    },
                    logLevel: "error",
                });
            }).toThrow(/sessionFs\.sessionStatePath is required/);
        });
    });

    describe("Auth options", () => {
        it("should accept gitHubToken option", () => {
            const client = new CopilotClient({
                gitHubToken: "gho_test_token",
                logLevel: "error",
            });

            expect((client as any).options.gitHubToken).toBe("gho_test_token");
        });

        it("should default useLoggedInUser to true when no gitHubToken", () => {
            const client = new CopilotClient({
                logLevel: "error",
            });

            expect((client as any).options.useLoggedInUser).toBe(true);
        });

        it("should default useLoggedInUser to false when gitHubToken is provided", () => {
            const client = new CopilotClient({
                gitHubToken: "gho_test_token",
                logLevel: "error",
            });

            expect((client as any).options.useLoggedInUser).toBe(false);
        });

        it("should allow explicit useLoggedInUser: true with gitHubToken", () => {
            const client = new CopilotClient({
                gitHubToken: "gho_test_token",
                useLoggedInUser: true,
                logLevel: "error",
            });

            expect((client as any).options.useLoggedInUser).toBe(true);
        });

        it("should allow explicit useLoggedInUser: false without gitHubToken", () => {
            const client = new CopilotClient({
                useLoggedInUser: false,
                logLevel: "error",
            });

            expect((client as any).options.useLoggedInUser).toBe(false);
        });

        it("should accept baseDirectory option", () => {
            const client = new CopilotClient({
                baseDirectory: "/custom/copilot/home",
                logLevel: "error",
            });

            expect((client as any).options.baseDirectory).toBe("/custom/copilot/home");
        });

        it("should leave baseDirectory undefined when not provided", () => {
            const client = new CopilotClient({
                logLevel: "error",
            });

            expect((client as any).options.baseDirectory).toBeUndefined();
        });

        it("should throw error when gitHubToken is used with forUri", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forUri("localhost:8080"),
                    gitHubToken: "gho_test_token",
                    logLevel: "error",
                });
            }).toThrow(
                /gitHubToken and useLoggedInUser cannot be used with RuntimeConnection.forUri/
            );
        });

        it("should throw error when useLoggedInUser is used with forUri", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forUri("localhost:8080"),
                    useLoggedInUser: false,
                    logLevel: "error",
                });
            }).toThrow(
                /gitHubToken and useLoggedInUser cannot be used with RuntimeConnection.forUri/
            );
        });

        it("should throw error when env is used with forInProcess", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forInProcess(),
                    env: { FOO: "bar" },
                    logLevel: "error",
                });
            }).toThrow(/env is not supported with RuntimeConnection.forInProcess/);
        });

        it("should throw error when telemetry is used with forInProcess", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forInProcess(),
                    telemetry: { otlpEndpoint: "http://localhost:4318" },
                    logLevel: "error",
                });
            }).toThrow(/telemetry is not supported with RuntimeConnection.forInProcess/);
        });

        it("should throw error when workingDirectory is used with forInProcess", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forInProcess(),
                    workingDirectory: "/tmp",
                    logLevel: "error",
                });
            }).toThrow(/workingDirectory is not supported with RuntimeConnection.forInProcess/);
        });

        it("should throw error when env is set on both the client and a stdio connection", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forStdio({ env: { FOO: "conn" } }),
                    env: { FOO: "client" },
                    logLevel: "error",
                });
            }).toThrow(
                /Set environment variables via either the client-level env option or the connection/
            );
        });

        it("should throw error when env is set on both the client and a tcp connection", () => {
            expect(() => {
                new CopilotClient({
                    connection: RuntimeConnection.forTcp({ env: { FOO: "conn" } }),
                    env: { FOO: "client" },
                    logLevel: "error",
                });
            }).toThrow(
                /Set environment variables via either the client-level env option or the connection/
            );
        });

        it("should use the connection-level env for child-process transports", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forStdio({ env: { FOO: "from-conn" } }),
                logLevel: "error",
            });
            expect((client as any).resolvedEnv).toEqual({ FOO: "from-conn" });
        });

        it("should allow env on the client alone with a child-process transport", () => {
            const client = new CopilotClient({
                connection: RuntimeConnection.forStdio(),
                env: { FOO: "from-client" },
                logLevel: "error",
            });
            expect((client as any).resolvedEnv).toEqual({ FOO: "from-client" });
        });
    });

    describe("overridesBuiltInTool in tool definitions", () => {
        it("sends overridesBuiltInTool in tool definition on session.create", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            await client.createSession({
                onPermissionRequest: approveAll,
                tools: [
                    {
                        name: "grep",
                        description: "custom grep",
                        handler: async () => "ok",
                        overridesBuiltInTool: true,
                    },
                ],
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
            expect(payload.tools).toEqual([
                expect.objectContaining({ name: "grep", overridesBuiltInTool: true }),
            ]);
        });

        it("sends overridesBuiltInTool in tool definition on session.resume", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            // Mock sendRequest to capture the call without hitting the runtime
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string, params: any) => {
                    if (method === "session.resume") return { sessionId: params.sessionId };
                    throw new Error(`Unexpected method: ${method}`);
                });
            await client.resumeSession(session.sessionId, {
                onPermissionRequest: approveAll,
                tools: [
                    {
                        name: "grep",
                        description: "custom grep",
                        handler: async () => "ok",
                        overridesBuiltInTool: true,
                    },
                ],
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
            expect(payload.tools).toEqual([
                expect.objectContaining({ name: "grep", overridesBuiltInTool: true }),
            ]);
            spy.mockRestore();
        });
    });

    describe("defer in tool definitions", () => {
        it("sends defer in tool definition on session.create", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            await client.createSession({
                onPermissionRequest: approveAll,
                tools: [
                    {
                        name: "lookup_issue",
                        description: "Fetch issue details",
                        handler: async () => "ok",
                        defer: "auto",
                    },
                ],
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
            expect(payload.tools).toEqual([
                expect.objectContaining({ name: "lookup_issue", defer: "auto" }),
            ]);
        });

        it("sends defer in tool definition on session.resume", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string, params: any) => {
                    if (method === "session.resume") return { sessionId: params.sessionId };
                    throw new Error(`Unexpected method: ${method}`);
                });
            await client.resumeSession(session.sessionId, {
                onPermissionRequest: approveAll,
                tools: [
                    {
                        name: "lookup_issue",
                        description: "Fetch issue details",
                        handler: async () => "ok",
                        defer: "auto",
                    },
                ],
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
            expect(payload.tools).toEqual([
                expect.objectContaining({ name: "lookup_issue", defer: "auto" }),
            ]);
            spy.mockRestore();
        });
    });

    describe("agent parameter in session creation", () => {
        it("forwards agent in session.create request", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            await client.createSession({
                onPermissionRequest: approveAll,
                customAgents: [
                    {
                        name: "test-agent",
                        prompt: "You are a test agent.",
                    },
                ],
                agent: "test-agent",
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
            expect(payload.agent).toBe("test-agent");
            expect(payload.customAgents).toEqual([expect.objectContaining({ name: "test-agent" })]);
            expect(payload.customAgents[0].reasoningEffort).toBeUndefined();
        });

        it("forwards custom agent model and reasoning effort in session.create request", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            await client.createSession({
                onPermissionRequest: approveAll,
                customAgents: [
                    {
                        name: "model-agent",
                        prompt: "You are a model agent.",
                        model: "claude-haiku-4.5",
                        reasoningEffort: "high",
                    },
                ],
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
            expect(payload.customAgents).toEqual([
                expect.objectContaining({
                    name: "model-agent",
                    model: "claude-haiku-4.5",
                    reasoningEffort: "high",
                }),
            ]);
        });

        it("forwards agent in session.resume request", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string, params: any) => {
                    if (method === "session.resume") return { sessionId: params.sessionId };
                    throw new Error(`Unexpected method: ${method}`);
                });
            await client.resumeSession(session.sessionId, {
                onPermissionRequest: approveAll,
                customAgents: [
                    {
                        name: "test-agent",
                        prompt: "You are a test agent.",
                    },
                ],
                agent: "test-agent",
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
            expect(payload.agent).toBe("test-agent");
            spy.mockRestore();
        });
    });

    describe("onListModels", () => {
        it("calls onListModels handler instead of RPC when provided", async () => {
            const customModels: ModelInfo[] = [
                {
                    id: "my-custom-model",
                    name: "My Custom Model",
                    capabilities: {
                        supports: { vision: false, reasoningEffort: false },
                        limits: { max_context_window_tokens: 128000 },
                    },
                    billing: {
                        multiplier: 1.5,
                        tokenPrices: {
                            inputPrice: 2.0,
                            outputPrice: 8.0,
                            cachePrice: 0.5,
                            batchSize: 1000000,
                            contextMax: 128000,
                            longContext: {
                                inputPrice: 4.0,
                                outputPrice: 16.0,
                                cachePrice: 1.0,
                                contextMax: 1000000,
                            },
                        },
                    },
                },
            ];

            const handler = vi.fn().mockReturnValue(customModels);
            const client = new CopilotClient({ onListModels: handler });
            await client.start();
            onTestFinished(() => stopClient(client));

            const models = await client.listModels();
            expect(handler).toHaveBeenCalledTimes(1);
            expect(models).toEqual(customModels);
            expect(models[0].billing?.tokenPrices?.longContext?.contextMax).toBe(1000000);
        });

        it("caches onListModels results on subsequent calls", async () => {
            const customModels: ModelInfo[] = [
                {
                    id: "cached-model",
                    name: "Cached Model",
                    capabilities: {
                        supports: { vision: false, reasoningEffort: false },
                        limits: { max_context_window_tokens: 128000 },
                    },
                },
            ];

            const handler = vi.fn().mockReturnValue(customModels);
            const client = new CopilotClient({ onListModels: handler });
            await client.start();
            onTestFinished(() => stopClient(client));

            await client.listModels();
            await client.listModels();
            expect(handler).toHaveBeenCalledTimes(1); // Only called once due to caching
        });

        it("supports async onListModels handler", async () => {
            const customModels: ModelInfo[] = [
                {
                    id: "async-model",
                    name: "Async Model",
                    capabilities: {
                        supports: { vision: false, reasoningEffort: false },
                        limits: { max_context_window_tokens: 128000 },
                    },
                },
            ];

            const handler = vi.fn().mockResolvedValue(customModels);
            const client = new CopilotClient({ onListModels: handler });
            await client.start();
            onTestFinished(() => stopClient(client));

            const models = await client.listModels();
            expect(models).toEqual(customModels);
        });

        it("does not require client.start when onListModels is provided", async () => {
            const customModels: ModelInfo[] = [
                {
                    id: "no-start-model",
                    name: "No Start Model",
                    capabilities: {
                        supports: { vision: false, reasoningEffort: false },
                        limits: { max_context_window_tokens: 128000 },
                    },
                },
            ];

            const handler = vi.fn().mockReturnValue(customModels);
            const client = new CopilotClient({ onListModels: handler });

            const models = await client.listModels();
            expect(handler).toHaveBeenCalledTimes(1);
            expect(models).toEqual(customModels);
        });
    });

    describe("unexpected disconnection", () => {
        it("stops after the runtime exits even when its TCP peer stays open", async () => {
            const directory = mkdtempSync(join(tmpdir(), "copilot-surviving-tcp-peer-"));
            const runtimePath = join(directory, "runtime.js");
            const client = new CopilotClient({
                connection: RuntimeConnection.forTcp({ path: runtimePath }),
            });
            let peer: Socket | undefined;
            let serverConnection: MessageConnection | undefined;
            // Retain the peer after FIN, independently of the owned runtime process.
            const server = createServer({ allowHalfOpen: true }, (socket) => {
                peer = socket;
                serverConnection = createMessageConnection(
                    new StreamMessageReader(socket),
                    new StreamMessageWriter(socket)
                );
                serverConnection.onRequest("connect", () => ({
                    protocolVersion: getSdkProtocolVersion(),
                }));
                serverConnection.onRequest("session.create", (params) => ({
                    sessionId: params.sessionId,
                }));
                serverConnection.listen();
            });
            onTestFinished(async () => {
                peer?.destroy();
                serverConnection?.dispose();
                await client.forceStop();
                await new Promise<void>((resolve, reject) =>
                    server.close((error) => (error ? reject(error) : resolve()))
                );
                rmSync(directory, { recursive: true, force: true });
            });
            await new Promise<void>((resolve) => server.listen(0, "127.0.0.1", resolve));
            const address = server.address();
            if (!address || typeof address === "string") {
                throw new Error("Expected a TCP listening address");
            }
            writeFileSync(
                runtimePath,
                `console.log("listening on port ${address.port}"); setInterval(() => {}, 1000);`
            );
            await client.createSession({ onPermissionRequest: approveAll });
            const socket = client["socket"]!;
            const child = client["cliProcess"]!;
            const closed = once(socket, "close", { signal: AbortSignal.timeout(10_000) });
            const exited = once(child, "exit");
            expect(child.kill()).toBe(true);
            await exited;
            await closed;
            expect(client["state"]).toBe("disconnected");
            expect(await client.stop()).toEqual([]);
            expect(peer?.destroyed).toBe(false);
        });

        it("disconnects when the runtime exits before an inherited output pipe closes", async () => {
            const directory = mkdtempSync(join(tmpdir(), "copilot-inherited-output-"));
            const runtimePath = join(directory, "runtime.js");
            const holderPidPath = join(directory, "holder.pid");
            const jsonrpcPath = createRequire(import.meta.url).resolve("vscode-jsonrpc/node");
            writeFileSync(
                runtimePath,
                `
const { spawn } = require("node:child_process");
const { once } = require("node:events");
const { createMessageConnection, StreamMessageReader, StreamMessageWriter } = require(${JSON.stringify(jsonrpcPath)});
const holder = spawn(process.execPath, ["-e", "process.send('ready'); setInterval(() => {}, 1000);"], {
    stdio: ["ignore", process.stdout, process.stderr, "ipc"],
    // Survive the runtime's Windows kill-on-close job while retaining its pipes.
    detached: true,
    windowsHide: true,
});
require("node:fs").writeFileSync(${JSON.stringify(holderPidPath)}, String(holder.pid));
const ready = once(holder, "message");
const connection = createMessageConnection(new StreamMessageReader(process.stdin), new StreamMessageWriter(process.stdout));
connection.onRequest("connect", async () => {
    await ready;
    return { protocolVersion: ${getSdkProtocolVersion()} };
});
connection.onRequest("session.create", (params) => ({ sessionId: params.sessionId }));
connection.onRequest("ping", async () => {
    await connection.sendNotification("test.pingReceived");
    return new Promise(() => {});
});
connection.listen();
`
            );
            const client = new CopilotClient({
                connection: RuntimeConnection.forStdio({ path: runtimePath }),
            });
            let closedPromise: Promise<unknown> | undefined;
            const stopHolder = () => {
                if (existsSync(holderPidPath)) {
                    try {
                        process.kill(Number(readFileSync(holderPidPath, "utf8")));
                    } catch (error) {
                        if (
                            !(error instanceof Error && "code" in error && error.code === "ESRCH")
                        ) {
                            throw error;
                        }
                    }
                }
            };
            onTestFinished(async () => {
                stopHolder();
                await client.forceStop();
                await closedPromise;
                rmSync(directory, { recursive: true, force: true });
            });
            await client.start();

            let signal: AbortSignal | undefined;
            let started!: () => void;
            const toolStarted = new Promise<void>((resolve) => {
                started = resolve;
            });
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                tools: [
                    {
                        name: "blocked_tool",
                        description: "blocks until cancelled",
                        handler: async (_args, invocation) => {
                            signal = invocation.signal;
                            started();
                            await new Promise<void>((resolve) =>
                                invocation.signal?.addEventListener("abort", () => resolve(), {
                                    once: true,
                                })
                            );
                            return "cancelled";
                        },
                    },
                ],
            });
            (session as any)._handleBroadcastEvent({
                type: "external_tool.requested",
                data: {
                    requestId: "inherited-output-request",
                    sessionId: session.sessionId,
                    toolCallId: "inherited-output-tool",
                    toolName: "blocked_tool",
                    arguments: {},
                },
            });
            await toolStarted;
            const pingReceived = new Promise<void>((resolve) =>
                client["connection"]!.onNotification("test.pingReceived", resolve)
            );
            let pingError: unknown;
            const ping = client.ping().catch((error) => {
                pingError = error;
            });
            await pingReceived;
            const child = client["cliProcess"]!;
            const exited = once(child, "exit");
            closedPromise = once(child, "close");
            let closed = false;
            child.once("close", () => {
                closed = true;
            });
            child.kill();
            await exited;
            expect(() =>
                process.kill(Number(readFileSync(holderPidPath, "utf8")), 0)
            ).not.toThrow();
            await vi.waitFor(() =>
                expect(pingError).toMatchObject({
                    message: "Pending response rejected since connection got disposed",
                })
            );
            await ping;
            expect(closed).toBe(false);
            expect(client["state"]).toBe("disconnected");
            expect(signal?.aborted).toBe(true);
            stopHolder();
            await closedPromise;
        });

        // No child process exists over the in-process (FFI) transport, so this
        // child-process-kill scenario does not apply there. Covered by the default
        // (stdio) cell.
        it.skipIf((process.env.COPILOT_SDK_DEFAULT_CONNECTION ?? "").toLowerCase() === "inprocess")(
            "transitions to disconnected when child process is killed",
            async () => {
                const client = new CopilotClient();
                await client.start();
                onTestFinished(() => stopClient(client));
                vi.spyOn(client["connection"]!, "sendRequest").mockResolvedValueOnce({
                    models: [{ id: "before-restart" }],
                });
                expect((await client.listModels()).map((model) => model.id)).toEqual([
                    "before-restart",
                ]);
                let invocationSignal: AbortSignal | undefined;
                let toolStarted!: () => void;
                const started = new Promise<void>((resolve) => {
                    toolStarted = resolve;
                });
                const session = await client.createSession({
                    onPermissionRequest: approveAll,
                    tools: [
                        {
                            name: "blocked_tool",
                            description: "blocks until cancelled",
                            handler: async (_args, invocation) => {
                                invocationSignal = invocation.signal;
                                toolStarted();
                                await new Promise<void>((_, reject) =>
                                    invocation.signal?.addEventListener(
                                        "abort",
                                        () => reject(invocation.signal?.reason),
                                        { once: true }
                                    )
                                );
                            },
                        },
                    ],
                });
                (session as any)._handleBroadcastEvent({
                    type: "external_tool.requested",
                    data: {
                        requestId: "request-connection-close",
                        sessionId: session.sessionId,
                        toolCallId: "tool-call-connection-close",
                        toolName: "blocked_tool",
                        arguments: {},
                    },
                });
                await started;

                expect((client as any).state).toBe("connected");

                // Kill the child process to simulate unexpected termination
                const proc = (client as any)
                    .cliProcess as import("node:child_process").ChildProcess;
                proc.kill();

                // Wait for the connection.onClose handler to fire
                await vi.waitFor(() => {
                    expect((client as any).state).toBe("disconnected");
                    expect(invocationSignal?.aborted).toBe(true);
                });
                await expect(client.listModels()).rejects.toThrow("Client not connected");

                await client.start();
                expect(client["state"]).toBe("connected");
                await expect(client.ping("restarted")).resolves.toMatchObject({
                    message: "pong: restarted",
                });
                const sendRequest = vi
                    .spyOn(client["connection"]!, "sendRequest")
                    .mockResolvedValueOnce({ models: [{ id: "after-restart" }] });
                expect((await client.listModels()).map((model) => model.id)).toEqual([
                    "after-restart",
                ]);
                expect(sendRequest).toHaveBeenCalledWith("models.list", {});
            }
        );
    });

    describe("onGetTraceContext", () => {
        it("includes trace context from callback in session.create request", async () => {
            const traceContext = {
                traceparent: "00-abcdef1234567890abcdef1234567890-1234567890abcdef-01",
                tracestate: "vendor=opaque",
            };
            const provider = vi.fn().mockReturnValue(traceContext);
            const client = new CopilotClient({ onGetTraceContext: provider });
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            await client.createSession({ onPermissionRequest: approveAll });

            expect(provider).toHaveBeenCalled();
            expect(spy).toHaveBeenCalledWith(
                "session.create",
                expect.objectContaining({
                    traceparent: "00-abcdef1234567890abcdef1234567890-1234567890abcdef-01",
                    tracestate: "vendor=opaque",
                })
            );
        });

        it("includes trace context from callback in session.resume request", async () => {
            const traceContext = {
                traceparent: "00-abcdef1234567890abcdef1234567890-1234567890abcdef-01",
            };
            const provider = vi.fn().mockReturnValue(traceContext);
            const client = new CopilotClient({ onGetTraceContext: provider });
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string, params: any) => {
                    if (method === "session.resume") return { sessionId: params.sessionId };
                    throw new Error(`Unexpected method: ${method}`);
                });
            await client.resumeSession(session.sessionId, { onPermissionRequest: approveAll });

            expect(spy).toHaveBeenCalledWith(
                "session.resume",
                expect.objectContaining({
                    traceparent: "00-abcdef1234567890abcdef1234567890-1234567890abcdef-01",
                })
            );
        });

        it("includes trace context from callback in session.send request", async () => {
            const traceContext = {
                traceparent: "00-fedcba0987654321fedcba0987654321-abcdef1234567890-01",
            };
            const provider = vi.fn().mockReturnValue(traceContext);
            const client = new CopilotClient({ onGetTraceContext: provider });
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string) => {
                    if (method === "session.send") return { responseId: "r1" };
                    throw new Error(`Unexpected method: ${method}`);
                });
            await session.send({ prompt: "hello" });

            expect(spy).toHaveBeenCalledWith(
                "session.send",
                expect.objectContaining({
                    traceparent: "00-fedcba0987654321fedcba0987654321-abcdef1234567890-01",
                })
            );
        });

        it("forwards requestHeaders in session.send request", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string) => {
                    if (method === "session.send") return { messageId: "m1" };
                    throw new Error(`Unexpected method: ${method}`);
                });

            await session.send({
                prompt: "hello",
                requestHeaders: { Authorization: "Bearer turn-token" },
            });

            expect(spy).toHaveBeenCalledWith(
                "session.send",
                expect.objectContaining({
                    prompt: "hello",
                    requestHeaders: { Authorization: "Bearer turn-token" },
                })
            );
        });

        it("does not include trace context when no callback is provided", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            await client.createSession({ onPermissionRequest: approveAll });

            const [, params] = spy.mock.calls.find(([method]) => method === "session.create")!;
            expect(params.traceparent).toBeUndefined();
            expect(params.tracestate).toBeUndefined();
        });
    });

    describe("commands", () => {
        it("forwards commands in session.create RPC", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const spy = vi.spyOn((client as any).connection!, "sendRequest");
            await client.createSession({
                onPermissionRequest: approveAll,
                commands: [
                    { name: "deploy", description: "Deploy the app", handler: async () => {} },
                    { name: "rollback", handler: async () => {} },
                ],
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.create")![1] as any;
            expect(payload.commands).toEqual([
                { name: "deploy", description: "Deploy the app" },
                { name: "rollback", description: "" },
            ]);
        });

        it("forwards commands in session.resume RPC", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            const spy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string, params: any) => {
                    if (method === "session.resume") return { sessionId: params.sessionId };
                    throw new Error(`Unexpected method: ${method}`);
                });
            await client.resumeSession(session.sessionId, {
                onPermissionRequest: approveAll,
                commands: [{ name: "deploy", description: "Deploy", handler: async () => {} }],
            });

            const payload = spy.mock.calls.find((c) => c[0] === "session.resume")![1] as any;
            expect(payload.commands).toEqual([{ name: "deploy", description: "Deploy" }]);
            spy.mockRestore();
        });

        it("routes command.execute event to the correct handler", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const handler = vi.fn();
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                commands: [{ name: "deploy", handler }],
            });

            // Mock the RPC response so handlePendingCommand doesn't fail
            const rpcSpy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string) => {
                    if (method === "session.commands.handlePendingCommand")
                        return { success: true };
                    throw new Error(`Unexpected method: ${method}`);
                });

            // Simulate a command.execute event
            (session as any)._dispatchEvent({
                id: "evt-1",
                timestamp: new Date().toISOString(),
                parentId: null,
                ephemeral: true,
                type: "command.execute",
                data: {
                    requestId: "req-1",
                    command: "/deploy production",
                    commandName: "deploy",
                    args: "production",
                },
            });

            await vi.waitFor(() => expect(handler).toHaveBeenCalledTimes(1));
            expect(handler).toHaveBeenCalledWith(
                expect.objectContaining({
                    sessionId: session.sessionId,
                    command: "/deploy production",
                    commandName: "deploy",
                    args: "production",
                })
            );

            // Verify handlePendingCommand was called with the requestId
            expect(rpcSpy).toHaveBeenCalledWith(
                "session.commands.handlePendingCommand",
                expect.objectContaining({ requestId: "req-1" })
            );
            rpcSpy.mockRestore();
        });

        it("sends error when command handler throws", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({
                onPermissionRequest: approveAll,
                commands: [
                    {
                        name: "fail",
                        handler: () => {
                            throw new Error("deploy failed");
                        },
                    },
                ],
            });

            const rpcSpy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string) => {
                    if (method === "session.commands.handlePendingCommand")
                        return { success: true };
                    throw new Error(`Unexpected method: ${method}`);
                });

            (session as any)._dispatchEvent({
                id: "evt-2",
                timestamp: new Date().toISOString(),
                parentId: null,
                ephemeral: true,
                type: "command.execute",
                data: {
                    requestId: "req-2",
                    command: "/fail",
                    commandName: "fail",
                    args: "",
                },
            });

            await vi.waitFor(() =>
                expect(rpcSpy).toHaveBeenCalledWith(
                    "session.commands.handlePendingCommand",
                    expect.objectContaining({ requestId: "req-2", error: "deploy failed" })
                )
            );
            rpcSpy.mockRestore();
        });

        it("sends error for unknown command", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({
                onPermissionRequest: approveAll,
                commands: [{ name: "deploy", handler: async () => {} }],
            });

            const rpcSpy = vi
                .spyOn((client as any).connection!, "sendRequest")
                .mockImplementation(async (method: string) => {
                    if (method === "session.commands.handlePendingCommand")
                        return { success: true };
                    throw new Error(`Unexpected method: ${method}`);
                });

            (session as any)._dispatchEvent({
                id: "evt-3",
                timestamp: new Date().toISOString(),
                parentId: null,
                ephemeral: true,
                type: "command.execute",
                data: {
                    requestId: "req-3",
                    command: "/unknown",
                    commandName: "unknown",
                    args: "",
                },
            });

            await vi.waitFor(() =>
                expect(rpcSpy).toHaveBeenCalledWith(
                    "session.commands.handlePendingCommand",
                    expect.objectContaining({
                        requestId: "req-3",
                        error: expect.stringContaining("Unknown command"),
                    })
                )
            );
            rpcSpy.mockRestore();
        });
    });

    describe("ui elicitation", () => {
        it("reads capabilities from session.create response", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            // Intercept session.create to inject capabilities
            const origSendRequest = (client as any).connection!.sendRequest.bind(
                (client as any).connection
            );
            vi.spyOn((client as any).connection!, "sendRequest").mockImplementation(
                async (method: string, params: any) => {
                    if (method === "session.create") {
                        const result = await origSendRequest(method, params);
                        return {
                            ...result,
                            capabilities: { ui: { elicitation: true } },
                        };
                    }
                    return origSendRequest(method, params);
                }
            );

            const session = await client.createSession({ onPermissionRequest: approveAll });
            expect(session.capabilities).toEqual({ ui: { elicitation: true } });
        });

        it("defaults capabilities when not injected", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });
            // CLI returns actual capabilities (elicitation false in headless mode)
            expect(session.capabilities.ui?.elicitation).toBe(false);
        });

        it("elicitation throws when capability is missing", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({ onPermissionRequest: approveAll });

            await expect(
                session.ui.elicitation({
                    message: "Enter name",
                    requestedSchema: {
                        type: "object",
                        properties: { name: { type: "string", minLength: 1 } },
                        required: ["name"],
                    },
                })
            ).rejects.toThrow(/not supported/);
        });

        it("sends requestElicitation flag when onElicitationRequest is provided", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const rpcSpy = vi.spyOn((client as any).connection!, "sendRequest");

            const session = await client.createSession({
                onPermissionRequest: approveAll,
                onElicitationRequest: async () => ({
                    action: "accept" as const,
                    content: {},
                }),
            });
            expect(session).toBeDefined();

            const createCall = rpcSpy.mock.calls.find((c) => c[0] === "session.create");
            expect(createCall).toBeDefined();
            expect(createCall![1]).toEqual(
                expect.objectContaining({
                    requestElicitation: true,
                })
            );
            rpcSpy.mockRestore();
        });

        it("does not send requestElicitation when no handler provided", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const rpcSpy = vi.spyOn((client as any).connection!, "sendRequest");

            const session = await client.createSession({
                onPermissionRequest: approveAll,
            });
            expect(session).toBeDefined();

            const createCall = rpcSpy.mock.calls.find((c) => c[0] === "session.create");
            expect(createCall).toBeDefined();
            expect(createCall![1]).toEqual(
                expect.objectContaining({
                    requestElicitation: false,
                })
            );
            rpcSpy.mockRestore();
        });

        it("sends mode callback request flags based on handler presence", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const rpcSpy = vi.spyOn((client as any).connection!, "sendRequest");

            await client.createSession({
                onPermissionRequest: approveAll,
                onExitPlanModeRequest: () => ({ approved: true }),
                onAutoModeSwitchRequest: () => "yes_always",
            });

            const createCallWithHandlers = rpcSpy.mock.calls.find((c) => c[0] === "session.create");
            expect(createCallWithHandlers![1]).toEqual(
                expect.objectContaining({
                    requestExitPlanMode: true,
                    requestAutoModeSwitch: true,
                })
            );

            rpcSpy.mockClear();
            await client.createSession({ onPermissionRequest: approveAll });
            const createCallWithoutHandlers = rpcSpy.mock.calls.find(
                (c) => c[0] === "session.create"
            );
            expect(createCallWithoutHandlers![1]).toEqual(
                expect.objectContaining({
                    requestExitPlanMode: false,
                    requestAutoModeSwitch: false,
                })
            );
            rpcSpy.mockRestore();
        });

        it("dispatches mode callback requests to registered handlers", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({
                onPermissionRequest: approveAll,
                onExitPlanModeRequest: (request, invocation) => {
                    expect(invocation.sessionId).toBeDefined();
                    expect(request.summary).toBe("Review the plan");
                    expect(request.planContent).toBe("Plan body");
                    expect(request.actions).toEqual(["interactive", "autopilot"]);
                    expect(request.recommendedAction).toBe("autopilot");
                    return {
                        approved: true,
                        selectedAction: "interactive",
                        feedback: "Looks good",
                    };
                },
                onAutoModeSwitchRequest: (request, invocation) => {
                    expect(invocation.sessionId).toBeDefined();
                    expect(request.errorCode).toBe("user_weekly_rate_limited");
                    expect(request.retryAfterSeconds).toBe(3600);
                    return "yes_always";
                },
            });

            const exitResult = await (client as any).handleExitPlanModeRequest({
                sessionId: session.sessionId,
                summary: "Review the plan",
                planContent: "Plan body",
                actions: ["interactive", "autopilot"],
                recommendedAction: "autopilot",
            });
            expect(exitResult).toEqual({
                approved: true,
                selectedAction: "interactive",
                feedback: "Looks good",
            });

            const autoResult = await (client as any).handleAutoModeSwitchRequest({
                sessionId: session.sessionId,
                errorCode: "user_weekly_rate_limited",
                retryAfterSeconds: 3600,
            });
            expect(autoResult).toEqual({ response: "yes_always" });
        });

        it("sends cancel when elicitation handler throws", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const session = await client.createSession({
                onPermissionRequest: approveAll,
                onElicitationRequest: async () => {
                    throw new Error("handler exploded");
                },
            });

            const rpcSpy = vi.spyOn((client as any).connection!, "sendRequest");

            await session._handleElicitationRequest(
                { sessionId: session.sessionId, message: "Pick a color" },
                "req-123"
            );

            const cancelCall = rpcSpy.mock.calls.find(
                (c) =>
                    c[0] === "session.ui.handlePendingElicitation" &&
                    (c[1] as any)?.result?.action === "cancel"
            );
            expect(cancelCall).toBeDefined();
            expect(cancelCall![1]).toEqual(
                expect.objectContaining({
                    requestId: "req-123",
                    result: { action: "cancel" },
                })
            );
            rpcSpy.mockRestore();
        });
    });

    describe("sessionIdleTimeoutSeconds", () => {
        it("should default to 0 when not specified", () => {
            const client = new CopilotClient({
                logLevel: "error",
            });

            expect((client as any).options.sessionIdleTimeoutSeconds).toBe(0);
        });

        it("should store a custom value", () => {
            const client = new CopilotClient({
                sessionIdleTimeoutSeconds: 600,
                logLevel: "error",
            });

            expect((client as any).options.sessionIdleTimeoutSeconds).toBe(600);
        });
    });

    describe("hooks dispatcher", () => {
        // Direct unit tests for CopilotSession._handleHooksInvoke. The hook
        // dispatch logic maps the CLI-emitted hook type (string) to the
        // corresponding SessionHooks handler. These tests guard against
        // regressions like the one fixed for postToolUseFailure (issue #1220).

        it("dispatches postToolUseFailure to onPostToolUseFailure handler", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const received: { input: any; invocation: any }[] = [];
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                hooks: {
                    onPostToolUseFailure: async (input, invocation) => {
                        received.push({ input, invocation });
                        return { additionalContext: "failure observed" };
                    },
                },
            });

            const failureInput = {
                toolName: "failing-tool",
                toolArgs: { foo: "bar" },
                error: "exit 1",
                timestamp: 1234,
                cwd: "/tmp",
            };
            const expectedInput = {
                toolName: "failing-tool",
                toolArgs: { foo: "bar" },
                error: "exit 1",
                timestamp: new Date(1234),
                workingDirectory: "/tmp",
            };
            const result = await (session as any)._handleHooksInvoke(
                "postToolUseFailure",
                failureInput
            );

            expect(received).toHaveLength(1);
            expect(received[0].input).toEqual(expectedInput);
            expect(received[0].invocation.sessionId).toBe(session.sessionId);
            expect(result).toEqual({ additionalContext: "failure observed" });
        });

        it("does not fall back to onPostToolUse for postToolUseFailure events", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const postUseCalls: string[] = [];
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                hooks: {
                    // Only onPostToolUse registered; postToolUseFailure events
                    // must not be routed here.
                    onPostToolUse: async (input) => {
                        postUseCalls.push(input.toolName);
                    },
                },
            });

            const result = await (session as any)._handleHooksInvoke("postToolUseFailure", {
                toolName: "failing-tool",
                toolArgs: {},
                error: "boom",
                timestamp: 0,
                cwd: "/tmp",
            });

            expect(postUseCalls).toHaveLength(0);
            expect(result).toBeUndefined();
        });

        it("dispatches postToolUse and postToolUseFailure to their respective handlers", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const postCalls: string[] = [];
            const failureCalls: string[] = [];
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                hooks: {
                    onPostToolUse: async (input) => {
                        postCalls.push(input.toolName);
                    },
                    onPostToolUseFailure: async (input) => {
                        failureCalls.push(input.toolName);
                    },
                },
            });

            await (session as any)._handleHooksInvoke("postToolUse", {
                toolName: "success-tool",
                toolArgs: {},
                toolResult: {
                    textResultForLlm: "ok",
                    resultType: "success" as const,
                },
                timestamp: 0,
                cwd: "/tmp",
            });
            await (session as any)._handleHooksInvoke("postToolUseFailure", {
                toolName: "fail-tool",
                toolArgs: {},
                error: "bad",
                timestamp: 0,
                cwd: "/tmp",
            });

            expect(postCalls).toEqual(["success-tool"]);
            expect(failureCalls).toEqual(["fail-tool"]);
        });

        it("registers hooks.invoke on the JSON-RPC connection and routes it to handleHooksInvoke", async () => {
            const client = new CopilotClient();
            const handleHooksInvoke = vi
                .spyOn(client as any, "handleHooksInvoke")
                .mockResolvedValue({ output: { additionalContext: "ok" } });

            const fakeConnection = {
                onNotification: vi.fn(),
                onRequest: vi.fn(),
                onClose: vi.fn(),
                onError: vi.fn(),
            };

            (client as any).connection = fakeConnection;
            (client as any).attachConnectionHandlers();

            const hooksRegistration = fakeConnection.onRequest.mock.calls.find(
                ([method]: [string, unknown]) => method === "hooks.invoke"
            );
            expect(hooksRegistration).toBeDefined();

            const handler = hooksRegistration![1] as (params: {
                sessionId: string;
                hookType: string;
                input: unknown;
            }) => Promise<{ output?: unknown }>;
            const payload = {
                sessionId: "session-1",
                hookType: "postToolUseFailure",
                input: { toolName: "shell" },
            };

            await expect(handler(payload)).resolves.toEqual({
                output: { additionalContext: "ok" },
            });
            expect(handleHooksInvoke).toHaveBeenCalledWith(payload);
        });

        it("routes hooks.invoke JSON-RPC requests to the SessionHooks handler", async () => {
            // Validates the dispatch behavior for the internal `hooks.invoke`
            // payload after the JSON-RPC connection hands it to the SDK.
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const received: { input: any; invocation: any }[] = [];
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                hooks: {
                    onPostToolUseFailure: async (input, invocation) => {
                        received.push({ input, invocation });
                        return { additionalContext: "context from failure hook" };
                    },
                },
            });

            const failureInput = {
                toolName: "shell",
                toolArgs: { command: "false" },
                error: "exit 1",
                timestamp: 1700000000000,
                cwd: "/tmp",
            };

            const response = await (client as any).handleHooksInvoke({
                sessionId: session.sessionId,
                hookType: "postToolUseFailure",
                input: failureInput,
            });

            expect(received).toHaveLength(1);
            expect(received[0].input).toEqual({
                toolName: "shell",
                toolArgs: { command: "false" },
                error: "exit 1",
                timestamp: new Date(1700000000000),
                workingDirectory: "/tmp",
            });
            expect(received[0].invocation.sessionId).toBe(session.sessionId);
            // The CLI only consumes output.additionalContext; the SDK returns
            // it wrapped in `{ output }` per the JSON-RPC contract.
            expect(response).toEqual({
                output: { additionalContext: "context from failure hook" },
            });
        });

        it("dispatches agentStop to onAgentStop and returns a block decision", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const received: { input: any; invocation: any }[] = [];
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                hooks: {
                    onAgentStop: async (input, invocation) => {
                        received.push({ input, invocation });
                        return { decision: "block", reason: "2 vulnerabilities found; please fix" };
                    },
                },
            });

            const result = await (session as any)._handleHooksInvoke("agentStop", {
                stopReason: "end_turn",
                transcriptPath: "/tmp/transcript.jsonl",
                stop_hook_active: true,
                timestamp: 1700000000000,
                cwd: "/repo",
            });

            expect(received).toHaveLength(1);
            expect(received[0].input).toEqual({
                stopReason: "end_turn",
                transcriptPath: "/tmp/transcript.jsonl",
                stopHookActive: true,
                timestamp: new Date(1700000000000),
                workingDirectory: "/repo",
            });
            expect(received[0].invocation.sessionId).toBe(session.sessionId);
            expect(result).toEqual({
                decision: "block",
                reason: "2 vulnerabilities found; please fix",
            });
        });

        it("routes agentStop hooks.invoke JSON-RPC requests to onAgentStop", async () => {
            const client = new CopilotClient();
            await client.start();
            onTestFinished(() => stopClient(client));

            const received: { input: any }[] = [];
            const session = await client.createSession({
                onPermissionRequest: approveAll,
                hooks: {
                    onAgentStop: async (input) => {
                        received.push({ input });
                        // Returning nothing lets the agent stop normally.
                    },
                },
            });

            const response = await (client as any).handleHooksInvoke({
                sessionId: session.sessionId,
                hookType: "agentStop",
                input: {
                    stopReason: "end_turn",
                    stop_hook_active: true,
                    timestamp: 1700000000000,
                    cwd: "/repo",
                },
            });

            expect(received).toHaveLength(1);
            expect(received[0].input).toEqual({
                stopReason: "end_turn",
                stopHookActive: true,
                timestamp: new Date(1700000000000),
                workingDirectory: "/repo",
            });
            // No decision returned — the SDK forwards an empty output envelope.
            expect(response).toEqual({ output: undefined });
        });

        it("routes subagentStart hooks.invoke with normalized parent metadata and additional context", async () => {
            const client = new CopilotClient({ autoStart: false });

            const received: { input: unknown; invocation: { sessionId: string } }[] = [];
            const session = new CopilotSession("session-1", {} as any);
            session.registerHooks({
                onSubagentStart: async (input, invocation) => {
                    received.push({ input, invocation });
                    return {
                        additionalContext: "Read the requested file.",
                    } satisfies SubagentStartHookOutput;
                },
            });
            (client as any).sessions.set(session.sessionId, session);

            const response = await (client as any).handleHooksInvoke({
                sessionId: session.sessionId,
                hookType: "subagentStart",
                input: {
                    sessionId: "parent-runtime-id",
                    timestamp: 1700000000000,
                    cwd: "/repo",
                    transcriptPath: "/repo/transcript.jsonl",
                    agentName: "explore",
                    agentDisplayName: "Explore Agent",
                    agentDescription: "Reads files",
                },
            });

            expect(received).toEqual([
                {
                    input: {
                        sessionId: "parent-runtime-id",
                        timestamp: new Date(1700000000000),
                        workingDirectory: "/repo",
                        transcriptPath: "/repo/transcript.jsonl",
                        agentName: "explore",
                        agentDisplayName: "Explore Agent",
                        agentDescription: "Reads files",
                    },
                    invocation: { sessionId: session.sessionId },
                },
            ]);
            expect(response).toEqual({ output: { additionalContext: "Read the requested file." } });
        });

        it("routes subagentStop hooks.invoke with its response and forwards an explicit allow and rewrite", async () => {
            const client = new CopilotClient({ autoStart: false });

            const received: { input: unknown; invocation: { sessionId: string } }[] = [];
            const session = new CopilotSession("session-1", {} as any);
            session.registerHooks({
                onSubagentStop: (input, invocation) => {
                    received.push({ input, invocation });
                    return {
                        decision: "allow",
                        modifiedResponse: "Reviewed: " + input.response,
                    } satisfies SubagentStopHookOutput;
                },
            });
            (client as any).sessions.set(session.sessionId, session);

            const response = await (client as any).handleHooksInvoke({
                sessionId: session.sessionId,
                hookType: "subagentStop",
                input: {
                    sessionId: "parent-runtime-id",
                    timestamp: 1700000000000,
                    cwd: "/repo",
                    transcriptPath: "/repo/transcript.jsonl",
                    agentId: "read-file",
                    agentType: "explore",
                    agentName: "explore",
                    stopReason: "end_turn",
                    response: "The file contains a greeting.",
                },
            });

            expect(received).toEqual([
                {
                    input: {
                        sessionId: "parent-runtime-id",
                        timestamp: new Date(1700000000000),
                        workingDirectory: "/repo",
                        transcriptPath: "/repo/transcript.jsonl",
                        agentId: "read-file",
                        agentType: "explore",
                        agentName: "explore",
                        stopReason: "end_turn",
                        response: "The file contains a greeting.",
                    },
                    invocation: { sessionId: session.sessionId },
                },
            ]);
            expect(response).toEqual({
                output: {
                    decision: "allow",
                    modifiedResponse: "Reviewed: The file contains a greeting.",
                },
            });
        });

        it("forwards a subagentStop block reason without invoking the top-level agentStop hook", async () => {
            const client = new CopilotClient({ autoStart: false });

            const topLevelStop = vi.fn();
            const session = new CopilotSession("session-1", {} as any);
            session.registerHooks({
                onAgentStop: topLevelStop,
                onSubagentStop: () =>
                    ({
                        decision: "block",
                        reason: "Read the rest of the file.",
                    }) satisfies SubagentStopHookOutput,
            });
            (client as any).sessions.set(session.sessionId, session);

            const response = await (client as any).handleHooksInvoke({
                sessionId: session.sessionId,
                hookType: "subagentStop",
                input: {
                    sessionId: session.sessionId,
                    timestamp: 1700000000000,
                    cwd: "/repo",
                    transcriptPath: "/repo/transcript.jsonl",
                    agentType: "explore",
                    agentName: "explore",
                    stopReason: "end_turn",
                    response: "First line",
                },
            });

            expect(response).toEqual({
                output: { decision: "block", reason: "Read the rest of the file." },
            });
            expect(topLevelStop).not.toHaveBeenCalled();
        });
    });

    describe("shutdown", () => {
        it.each(["stop", "forceStop"] as const)(
            "%s cancels pending inference requests before transport teardown",
            async (method) => {
                const client = new CopilotClient({ autoStart: false });
                const cancelPending = vi.fn();
                (client as any).requestAdapter = { cancelPending };

                await client[method]();

                expect(cancelPending).toHaveBeenCalledTimes(1);
            }
        );

        it.each(["stop", "forceStop"] as const)(
            "%s waits for the initial in-process cleanup attempt",
            async (method) => {
                const client = new CopilotClient({
                    connection: RuntimeConnection.forInProcess(),
                });
                let finishCleanup!: () => void;
                const cleanup = new Promise<void>((resolve) => {
                    finishCleanup = resolve;
                });
                const dispose = vi.fn(() => cleanup);
                (client as any).ffiHost = { dispose };

                let stopped = false;
                const shutdown = client[method]().then(() => {
                    stopped = true;
                });
                await vi.waitFor(() => expect(dispose).toHaveBeenCalledTimes(1));
                expect(stopped).toBe(false);

                finishCleanup();
                await shutdown;
                expect(stopped).toBe(true);
            }
        );

        it("disconnects when the owned CLI exits before its connection closes", async () => {
            const client = new CopilotClient();
            const oldChild = new EventEmitter();
            const child = new EventEmitter();
            const createConnection = () => ({
                onNotification: vi.fn(),
                onRequest: vi.fn(),
                onClose: vi.fn(),
                onError: vi.fn(),
                drain: vi.fn(async () => {}),
                dispose: vi.fn(),
            });
            const oldConnection = createConnection();
            const connection = createConnection();
            const finishDrain = Promise.withResolvers<void>();
            connection.drain.mockImplementation(() => finishDrain.promise);
            const sessionDisconnected = vi.fn();

            (client as any).connection = oldConnection;
            (client as any).cliProcess = oldChild;
            (client as any).attachConnectionHandlers();

            (client as any).connection = connection;
            (client as any).cliProcess = child;
            (client as any).connectionClosed = false;
            (client as any).state = "connected";
            (client as any).sessions.set("session-1", {
                _markDisconnected: sessionDisconnected,
            });
            (client as any).attachConnectionHandlers();

            oldChild.emit("exit", null, "SIGKILL");
            expect((client as any).state).toBe("connected");
            expect(sessionDisconnected).not.toHaveBeenCalled();

            child.emit("exit", null, "SIGKILL");
            expect((client as any).connectionClosed).toBe(true);
            expect(connection.drain).not.toHaveBeenCalled();
            expect(sessionDisconnected).not.toHaveBeenCalled();

            const onClose = connection.onClose.mock.calls[0]?.[0];
            expect(onClose).toBeDefined();
            onClose();
            expect(connection.drain).toHaveBeenCalledOnce();
            finishDrain.resolve();
            await vi.waitFor(() => {
                expect((client as any).state).toBe("disconnected");
                expect(sessionDisconnected).toHaveBeenCalledTimes(1);
            });
            expect((client as any).sessions.size).toBe(0);
            onClose();
            expect(sessionDisconnected).toHaveBeenCalledTimes(1);
        });

        it("disconnects after a bounded wait if an exited CLI leaves its reader open", async () => {
            const client = new CopilotClient();
            const child = new EventEmitter();
            const connection = {
                onNotification: vi.fn(),
                onRequest: vi.fn(),
                onClose: vi.fn(),
                onError: vi.fn(),
                drain: vi.fn(async () => {}),
                dispose: vi.fn(),
            };
            (client as any).connection = connection;
            (client as any).cliProcess = child;
            (client as any).state = "connected";
            (client as any).attachConnectionHandlers();

            vi.useFakeTimers();
            try {
                child.emit("exit", null, "SIGKILL");
                expect(connection.drain).not.toHaveBeenCalled();
                await vi.advanceTimersByTimeAsync(10_000);
                expect(connection.drain).toHaveBeenCalledOnce();
                expect((client as any).state).toBe("disconnected");
            } finally {
                vi.useRealTimers();
            }
        });

        it("does not keep the host alive while waiting for an exited CLI's reader", () => {
            const client = new CopilotClient();
            const child = new EventEmitter();
            const connection = {
                onNotification: vi.fn(),
                onRequest: vi.fn(),
                onClose: vi.fn(),
                onError: vi.fn(),
                drain: vi.fn(async () => {}),
                dispose: vi.fn(),
            };
            (client as any).connection = connection;
            (client as any).cliProcess = child;
            (client as any).attachConnectionHandlers();

            const timeoutSpy = vi.spyOn(globalThis, "setTimeout");
            try {
                child.emit("exit", null, "SIGKILL");
                const fallback = timeoutSpy.mock.results[0]?.value as NodeJS.Timeout | undefined;
                expect(fallback).toBeDefined();
                expect(fallback?.hasRef()).toBe(false);
            } finally {
                for (const call of timeoutSpy.mock.results) {
                    clearTimeout(call.value as NodeJS.Timeout);
                }
                timeoutSpy.mockRestore();
            }
        });

        it("finishes stopping when an exited CLI leaves its TCP peer open", async () => {
            const server = createServer({ allowHalfOpen: true });
            let peer: Socket | undefined;
            let socket: Socket | undefined;
            let timeout: NodeJS.Timeout | undefined;
            try {
                await new Promise<void>((resolve, reject) => {
                    server.once("error", reject);
                    server.listen(0, "127.0.0.1", () => {
                        server.off("error", reject);
                        resolve();
                    });
                });
                const address = server.address();
                if (!address || typeof address === "string") {
                    throw new Error("Expected a TCP server address");
                }
                const accepted = new Promise<Socket>((resolve) => {
                    server.once("connection", resolve);
                });
                const connectedSocket = createConnection(address.port, "127.0.0.1");
                socket = connectedSocket;
                await new Promise<void>((resolve, reject) => {
                    connectedSocket.once("connect", resolve);
                    connectedSocket.once("error", reject);
                });
                peer = await accepted;
                expect(peer.destroyed).toBe(false);
                expect(socket.destroyed).toBe(false);
                const client = new CopilotClient({
                    autoStart: false,
                    connection: RuntimeConnection.forTcp(),
                });
                (client as any).socket = socket;
                (client as any).connectionClosed = true;
                (client as any).cliProcess = { exitCode: null, signalCode: "SIGKILL" };

                const errors = await Promise.race([
                    client.stop(),
                    new Promise<never>((_, reject) => {
                        timeout = setTimeout(
                            () => reject(new Error("stop() waited for an exited CLI's TCP peer")),
                            5_000
                        );
                    }),
                ]);
                expect(errors).toEqual([]);
                expect(socket.destroyed).toBe(true);
            } finally {
                if (timeout) clearTimeout(timeout);
                socket?.destroy();
                peer?.destroy();
                if (server.listening) {
                    await new Promise<void>((resolve, reject) => {
                        server.close((error) => (error ? reject(error) : resolve()));
                    });
                }
            }
        });

        it("tears down an owned CLI when its connected TCP peer holds the socket open", async () => {
            const server = createServer({ allowHalfOpen: true });
            let peer: Socket | undefined;
            let socket: Socket | undefined;
            let stopping: Promise<Error[]> | undefined;
            try {
                await new Promise<void>((resolve, reject) => {
                    server.once("error", reject);
                    server.listen(0, "127.0.0.1", () => {
                        server.off("error", reject);
                        resolve();
                    });
                });
                const address = server.address();
                if (!address || typeof address === "string") {
                    throw new Error("Expected a TCP server address");
                }
                const accepted = new Promise<Socket>((resolve) =>
                    server.once("connection", resolve)
                );
                socket = createConnection(address.port, "127.0.0.1");
                await new Promise<void>((resolve, reject) => {
                    socket?.once("connect", resolve);
                    socket?.once("error", reject);
                });
                peer = await accepted;

                const client = new CopilotClient({
                    autoStart: false,
                    connection: RuntimeConnection.forTcp(),
                });
                const child = Object.assign(new EventEmitter(), {
                    exitCode: null as number | null,
                    signalCode: null as string | null,
                    kill: vi.fn(() => {
                        child.exitCode = 0;
                        child.emit("exit", 0, null);
                        return true;
                    }),
                });
                (client as any).socket = socket;
                (client as any).connectionClosed = false;
                (client as any).cliProcess = child;

                vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout"] });
                stopping = client.stop();
                expect(socket.destroyed).toBe(false);
                await vi.advanceTimersByTimeAsync(10_000);
                expect(socket.destroyed).toBe(true);
                expect(await stopping).toEqual([]);
                expect(child.kill).toHaveBeenCalledOnce();
            } finally {
                socket?.destroy();
                peer?.destroy();
                if (stopping) await stopping;
                vi.useRealTimers();
                if (server.listening) {
                    await new Promise<void>((resolve, reject) => {
                        server.close((error) => (error ? reject(error) : resolve()));
                    });
                }
            }
        });

        it("does not finish starting after the owned CLI exits before a buffered reply arrives", async () => {
            const paths = [resolve("plugins/core")];
            const client = new CopilotClient({ builtinPluginDirectories: paths });
            onTestFinished(() => client.forceStop());
            const child = Object.assign(new EventEmitter(), { kill: vi.fn() });
            const registration = Promise.withResolvers<object>();
            const sendRequest = vi.fn((method: string) => {
                if (method !== "plugins.builtin.set")
                    throw new Error(`Unexpected request: ${method}`);
                return registration.promise;
            });
            const connection = {
                onNotification: vi.fn(),
                onRequest: vi.fn(),
                onClose: vi.fn(),
                onError: vi.fn(),
                sendRequest,
                drain: vi.fn(async () => {}),
                dispose: vi.fn(),
            };
            vi.spyOn(client as any, "startCLIServer").mockImplementation(async () => {
                (client as any).cliProcess = child;
            });
            vi.spyOn(client as any, "connectToServer").mockImplementation(async () => {
                (client as any).connection = connection;
                (client as any).attachConnectionHandlers();
            });
            vi.spyOn(client as any, "verifyProtocolVersion").mockResolvedValue(undefined);

            const starting = client.start();
            await vi.waitFor(() =>
                expect(sendRequest).toHaveBeenCalledWith("plugins.builtin.set", { paths })
            );
            child.emit("exit", 1, null);
            expect((client as any).connectionClosed).toBe(true);
            registration.resolve({});

            await expect(starting).rejects.toThrow("CLI server connection closed during startup");
            expect((client as any).state).not.toBe("connected");
            expect(child.kill).toHaveBeenCalledWith("SIGKILL");
        });

        it("ignores a previous connection's late close while starting a replacement", async () => {
            const client = new CopilotClient();
            onTestFinished(() => client.forceStop());
            const oldChild = Object.assign(new EventEmitter(), { kill: vi.fn() });
            const child = Object.assign(new EventEmitter(), { kill: vi.fn() });
            const createConnection = () => ({
                onNotification: vi.fn(),
                onRequest: vi.fn(),
                onClose: vi.fn(),
                onError: vi.fn(),
                drain: vi.fn(async () => {}),
                dispose: vi.fn(),
            });
            const oldConnection = createConnection();
            const connection = createConnection();
            (client as any).connection = oldConnection;
            (client as any).cliProcess = oldChild;
            (client as any).attachConnectionHandlers();
            oldChild.emit("exit", 1, null);
            await vi.waitFor(() => expect((client as any).state).toBe("disconnected"));
            const oldClose = oldConnection.onClose.mock.calls[0]?.[0];
            expect(oldClose).toBeTypeOf("function");

            vi.spyOn(client as any, "startCLIServer").mockImplementation(async () => {
                oldClose();
                (client as any).cliProcess = child;
            });
            vi.spyOn(client as any, "connectToServer").mockImplementation(async () => {
                (client as any).connection = connection;
                (client as any).attachConnectionHandlers();
            });
            vi.spyOn(client as any, "verifyProtocolVersion").mockResolvedValue(undefined);

            await client.start();
            expect((client as any).state).toBe("connected");
            expect((client as any).connectionClosed).toBe(false);
        });

        it("requests runtime shutdown when stopping an SDK-owned process", async () => {
            const client = new CopilotClient();
            const calls: string[] = [];
            const child = new EventEmitter() as EventEmitter & {
                exitCode: number | null;
                signalCode: string | null;
                kill: ReturnType<typeof vi.fn>;
            };
            child.exitCode = null;
            child.signalCode = null;
            child.kill = vi.fn(() => {
                calls.push("kill");
                child.signalCode = "SIGTERM";
                child.emit("exit", null, "SIGTERM");
                return true;
            });

            (client as any).connection = {
                sendRequest: vi.fn(async (method: string) => {
                    calls.push(method);
                    if (method === "runtime.shutdown") {
                        child.exitCode = 0;
                        child.emit("exit", 0, null);
                        return {};
                    }
                    throw new Error(`unexpected method ${method}`);
                }),
                dispose: vi.fn(() => calls.push("dispose")),
            };
            (client as any).cliProcess = child;
            (client as any).isExternalServer = false;

            await expect(client.stop()).resolves.toEqual([]);
            expect(calls).toEqual(["runtime.shutdown", "dispose"]);
            expect(child.kill).not.toHaveBeenCalled();
        });

        it("does not request runtime shutdown for force stop or external runtimes", async () => {
            const forceClient = new CopilotClient();
            const forceChild = new EventEmitter() as EventEmitter & {
                exitCode: number | null;
                signalCode: string | null;
                kill: ReturnType<typeof vi.fn>;
            };
            forceChild.exitCode = null;
            forceChild.signalCode = null;
            forceChild.kill = vi.fn(() => true);
            const forceSendRequest = vi.fn();
            (forceClient as any).connection = {
                sendRequest: forceSendRequest,
                dispose: vi.fn(),
            };
            (forceClient as any).cliProcess = forceChild;
            (forceClient as any).isExternalServer = false;

            await forceClient.forceStop();
            expect(forceSendRequest).not.toHaveBeenCalled();
            expect(forceChild.kill).toHaveBeenCalledWith("SIGKILL");

            const externalClient = new CopilotClient();
            const externalSendRequest = vi.fn();
            (externalClient as any).connection = {
                sendRequest: externalSendRequest,
                dispose: vi.fn(),
            };
            (externalClient as any).isExternalServer = true;

            await expect(externalClient.stop()).resolves.toEqual([]);
            expect(externalSendRequest).not.toHaveBeenCalled();
        });
    });
});

describe("managedSettings serialization", () => {
    async function captureCreateParams(config: Record<string, unknown>): Promise<any> {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.createSession({ onPermissionRequest: approveAll, ...config });
        const call = spy.mock.calls.find(([method]) => method === "session.create");
        return call![1];
    }

    it("forwards the full permissions object on session.create", async () => {
        const managedSettings = {
            permissions: {
                disableBypassPermissionsMode: DisableBypassPermissionsModes.AllowAutoOnly,
                disableAssistedPermissionsMode: true,
                deny: ["Shell(git push)"],
                ask: ["Domain(publish.example)"],
                allow: ["Read(**)"],
                limitTo: ["Domain(api.github.com)"],
            },
        } satisfies ManagedSettings;
        const params = await captureCreateParams({
            managedSettings,
        });
        expect(params.managedSettings).toEqual({
            permissions: {
                disableBypassPermissionsMode: "allow-auto-only",
                disableAssistedPermissionsMode: true,
                deny: ["Shell(git push)"],
                ask: ["Domain(publish.example)"],
                allow: ["Read(**)"],
                limitTo: ["Domain(api.github.com)"],
            },
        });
    });

    it("forwards the disable bypass-permissions mode", async () => {
        const managedSettings = {
            permissions: {
                disableBypassPermissionsMode: DisableBypassPermissionsModes.Disable,
            },
        } satisfies ManagedSettings;
        const params = await captureCreateParams({ managedSettings });

        expect(params.managedSettings).toEqual({
            permissions: {
                disableBypassPermissionsMode: "disable",
            },
        });
    });

    it("forwards unknown bypass-permissions modes", async () => {
        const managedSettings = {
            permissions: {
                disableBypassPermissionsMode: "future-fail-closed-mode",
            },
        } satisfies ManagedSettings;
        const params = await captureCreateParams({ managedSettings });

        expect(params.managedSettings).toEqual(managedSettings);
    });

    it("marks directly injected sessions as managed", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));
        vi.spyOn((client as any).connection!, "sendRequest").mockImplementation(
            async (method: string, params: any) => {
                if (method === "session.create") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            }
        );

        const session = await client.createSession({
            onPermissionRequest: approveAll,
            managedSettings: { permissions: { deny: ["Edit(/secrets/**)"] } },
        });

        expect((session as any).managedSettingsEnabled).toBe(true);
    });

    it("omits managedSettings when not supplied", async () => {
        const params = await captureCreateParams({});
        expect(params.managedSettings).toBeUndefined();
    });

    it("coexists with enableManagedSettings", async () => {
        const params = await captureCreateParams({
            enableManagedSettings: true,
            enforceManagedModelDefaults: true,
            managedSettings: { permissions: { deny: ["Edit(/secrets/**)"] } },
        });
        expect(params.enableManagedSettings).toBe(true);
        expect(params.enforceManagedModelDefaults).toBe(true);
        expect(params.managedSettings).toEqual({ permissions: { deny: ["Edit(/secrets/**)"] } });
    });

    it("preserves empty arrays in the permissions object", async () => {
        const params = await captureCreateParams({
            managedSettings: { permissions: { deny: [], ask: [], allow: [], limitTo: [] } },
        });
        expect(params.managedSettings).toEqual({
            permissions: { deny: [], ask: [], allow: [], limitTo: [] },
        });
    });

    it("forwards managedSettings on session.resume", async () => {
        const client = new CopilotClient();
        await client.start();
        onTestFinished(() => stopClient(client));
        const spy = vi
            .spyOn((client as any).connection!, "sendRequest")
            .mockImplementation(async (method: string, params: any) => {
                if (method === "session.resume") return { sessionId: params.sessionId };
                throw new Error(`Unexpected method: ${method}`);
            });
        await client.resumeSession("session-1", {
            onPermissionRequest: approveAll,
            managedSettings: { permissions: { ask: ["Domain(publish.example)"] } },
        });
        const call = spy.mock.calls.find(([method]) => method === "session.resume");
        expect(call![1].managedSettings).toEqual({
            permissions: { ask: ["Domain(publish.example)"] },
        });
    });
});

describe("connect handshake clientInfo", () => {
    // Drives verifyProtocolVersion() against a stubbed connection so we can
    // observe the `connect` params without spawning a runtime. `connect` maps to
    // connection.sendRequest("connect", params) in the generated internal RPC.
    async function captureConnectParams(
        options: Partial<Pick<CopilotClientOptions, "clientInfo" | "onGitHubTelemetry">> = {}
    ): Promise<Record<string, unknown>> {
        const client = new CopilotClient({
            connection: RuntimeConnection.forUri("localhost:1234"),
            ...options,
        });
        const sendRequest = vi.fn(async (method: string, _params?: unknown) => {
            if (method === "connect") return { protocolVersion: 3 };
            throw new Error(`Unexpected method: ${method}`);
        });
        (client as any).connection = { sendRequest };

        await (client as any).verifyProtocolVersion();

        const connectCall = sendRequest.mock.calls.find(([method]) => method === "connect");
        expect(connectCall, "connect was not called").toBeTruthy();
        return connectCall![1] as Record<string, unknown>;
    }

    it("forwards a declared client identity on the connect handshake", async () => {
        const clientInfo = {
            applicationName: "acme-developer-portal",
            applicationVersion: "2.4.0",
            integrationName: "copilot-assistant",
            integrationVersion: "1.5.0",
        };

        const params = await captureConnectParams({ clientInfo });

        expect(params.clientInfo).toEqual({
            editorName: "acme-developer-portal",
            editorVersion: "2.4.0",
            extensionName: "copilot-assistant",
            extensionVersion: "1.5.0",
        });
    });

    it("omits clientInfo from the handshake when the host declares none", async () => {
        const params = await captureConnectParams();

        expect(params).not.toHaveProperty("clientInfo");
        expect(params.supportedTaskKinds).toEqual(["agent", "client", "shell"]);
    });

    it("drops empty fields and omits an all-empty identity", async () => {
        const allEmpty = await captureConnectParams({
            clientInfo: {
                applicationName: "",
                applicationVersion: "",
                integrationName: "",
                integrationVersion: "",
            },
        });
        expect(allEmpty).not.toHaveProperty("clientInfo");

        const partial = await captureConnectParams({
            clientInfo: { applicationName: "example-app", applicationVersion: "" },
        });
        expect(partial.clientInfo).toEqual({ editorName: "example-app" });
    });

    it("keeps telemetry forwarding alongside a declared identity", async () => {
        const params = await captureConnectParams({
            clientInfo: { applicationName: "example-app" },
            onGitHubTelemetry: () => {},
        });

        expect(params).toMatchObject({
            clientInfo: { editorName: "example-app" },
            enableGitHubTelemetryForwarding: true,
        });
    });
});