reload d.ts modules in runtime

[jonnytest1]

wih node you can (while the server is still running)
do
delete require.cache[modulepath] require(modulepath)
to completely reload a module from the disk

but i didnt find any way to "unload" a .d.ts file 🤔maybe its also enough to restart the kanguage server if thats possible idk about the internals

[agammann]

A .d.ts file supplies declarations to TypeScript's type checker; it does not supply a runtime implementation to Node's require.cache. Deleting a CommonJS cache entry therefore won't unload its types.

For a normal ts-node development process, restart the process after changing declarations so it creates a fresh compiler service. Deleting a Node module cache entry is not a compiler-service reset.

I checked this with ts-node 10.9.2 / TypeScript 5.9.3: an entry point loaded a global declaration using files: true; after changing the declared property from string to number, a fresh ts-node invocation picked up the change and reported the expected type error. This verifies the restart approach, not hot reloading an existing language-service instance.

Restarting your editor's language server only refreshes that editor's diagnostics. It does not restart the separate ts-node process running your server. See how ts-node works and watching/restarting.

[jonnytest1]

Of cause restarting the editor typescript runtime has no bearing on the matter (not sure wh ud even try to verify that) im talking about the language Server in the running node process, also this is not a 'default use case' issue , im explicitly talking about got reloading a module and lack of support for Hot reloading dts files

[agammann]

You're right—I misunderstood the scope. You're asking about refreshing .d.ts declarations in the compiler service within the running Node process during module hot reload. My test only covered starting a fresh ts-node process, so it doesn't answer that question.