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Failed function argument type inference inside nested object passed as argument #22715
Description
TypeScript Version: 2.7.1
Search Terms: infer
Code
interface IFooOptions<K extends string> {
name?: string;
value?: number;
allFoos?: {[key in K]?: boolean }
fn?: (allFoos: {[key in K]: string }) => void;
}
class Bar<T> {
constructor(foos: {[key in keyof T]: IFooOptions<keyof T> }) {
// ...
}
}
const bar = new Bar({
firstFoo: {
name: "john",
value: 3,
allFoos: { // here allFoos infered
firstFoo: true,
nonexist: 'yep'
}
},
secondFoo: {
name: 'sandra',
fn: allFoos => { // but here allFoos is any though the type of "fn" is infered correctly
allFoos.nonexist = 2
}
}
});
const myFoo: IFooOptions<'one' | 'two'> = {
name: 'adas',
fn: allFoos => { //allFoos is infered right
allFoos.nonexist = 2
}
}Expected behavior:
The allFoos argument inside fn field in the new Bar argument should have a type of
{
firstFoo: string
secondFoo: string
}Actual behavior:
allFoos type is implicit any
Also it repoduces without using a class, just with plain generic function
Activity
RyanCavanaugh commentedon Mar 20, 2018
Nathan Shively-Sanders (@sandersn) is this a duplicate of #22362 ?
beshanoe commentedon Mar 22, 2018
Andy (Andrewkraft) (@Andy-MS) regarding argument, I was saying about this place:
if you remove error line "nonexistent": "yep", you will see that fn's type is inferred when I hover it, however allFoos argument is any
beshanoe commentedon Apr 16, 2018
Andy (Andrewkraft) (@Andy-MS) could you please explain your latest statement? Is it a bug? To me it looks like it is :)
I've encountered the same thing again, and it really prevents me from doing good typing in my app.
It's reproduced in 2.8.1 version
Here's is another example:
https://www.typescriptlang.org/play/index.html#src=class%20RouterProps%3CP%3E%20%7B%0D%0A%20%20props%3A%20P%0D%0A%7D%0D%0A%0D%0Aclass%20Component%3CP%3E%20%7B%0D%0A%20%20props%3A%20P%0D%0A%7D%0D%0A%0D%0A%2F%2F%20in%20'resolve'%20field%20I%20want%20to%20pass%20an%20object%20with%20keys%20from%20passed%20component's%20props%20and%20with%20functions%20as%20values%0D%0Ainterface%20IRoute%3CP%20%3D%20any%2C%20RP%20%3D%20any%3E%20%7B%0D%0A%20%20name%3A%20string%0D%0A%20%20component%3A%20Component%3CP%20%26%20RouterProps%3CRP%3E%3E%2C%0D%0A%20%20resolve%3F%3A%20%7B%20%5Bname%20in%20keyof%20P%5D%3F%3A%20(params%3A%20RP)%20%3D%3E%20Promise%3CP%5Bname%5D%3E%20%7D%0D%0A%7D%0D%0A%0D%0Afunction%20route%3CP%2C%20RP%3E(route%3A%20IRoute%3CP%2C%20RP%3E)%20%7B%0D%0A%20%20return%20route%0D%0A%7D%0D%0A%0D%0Aconst%20cmp%20%3D%20new%20Component%3C%7B%20foo%3A%20number%2C%20bar%3A%20string%20%7D%20%26%20RouterProps%3C%7B%20id%3A%20string%20%7D%3E%3E()%0D%0A%0D%0A%0D%0A%2F%2F%20if%20you%20hover%20'resolve'%20or%20'foo'%20object's%20field%2C%20the%20type%20is%20inferred%20correctly%2C%20saying%20that%20'params'%20arg%20is%20of%20type%20%7Bid%3A%20string%7D%0D%0A%2F%2F%20but%20when%20you%20hover%20'params'%2C%20it%20says%20that%20it's%20'any'%0D%0Aroute(%7B%0D%0A%20%20name%3A%20'sample-route'%2C%0D%0A%20%20component%3A%20cmp%2C%0D%0A%20%20resolve%3A%20%7B%0D%0A%20%20%20%20foo%3A%20params%20%3D%3E%20%7B%0D%0A%20%20%20%20%20%20alert(params.nonexistent)%20%2F%2F%20no%20error%20here%2C%20but%20should%20be%0D%0A%20%20%20%20%20%20return%20Promise.resolve(10)%20%2F%2F%20notice%20that%20the%20type%20of%20return%20value%20is%20enforced%2C%20namely%20change%2010%20to%20%22somestring%22%20and%20there%20will%20be%20an%20error%0D%0A%20%20%20%20%7D%0D%0A%20%20%7D%0D%0A%7D)
beshanoe commentedon Apr 16, 2018
Andy (Andrewkraft) (@Andy-MS) cool thanks, do you think this issue is a "good first issue"? Or it's too complicated? I just want to try to start contributing to TS :)
RyanCavanaugh commentedon Sep 16, 2019
This has been fixed (verified in 3.6)