Generic inference issue with callbacks

[sampbarrow]

Bug Report

🔎 Search Terms

Generic object inference, Generic object inference based on properties, Generic object inference callback.

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________

⏯ Playground Link

https://www.typescriptlang.org/play?#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

💻 Code

type Combo<Works, DoesntWork> = {
	test1: () => Works
	test2: (value: string) => DoesntWork
	func1: (value: Works) => string
	func2: (value: DoesntWork) => string
}
class ComboClass<T, V> {
	constructor(readonly definition: Combo<T, V>) {
	}
}
//Doesn't work
const combo1 = new ComboClass({
	test1: () => 1,
	test2: (value) => 2,
	func1: value => value.toLocaleString(),
	func2: value => value.toLocaleString(),//ERROR - value is of type unknown
})
//Works
const combo2 = new ComboClass({
	test1: () => 1,
	test2: (value: string) => 2, //I have to specify value: string - even though it's not generic - it's always string. Within this function, the compiler knows it's a string, but it breaks the inference for some reason.
	func1: value => value.toLocaleString(),
	func2: value => value.toLocaleString(),
})

🙁 Actual behavior

🙂 Expected behavior

See code comments.

[RyanCavanaugh]

TypeScript doesn't do multiple "rounds" of inference as would be required here. See #30134

[jcalz]

Fixed by #48538, right?