'this' not inferred for immediately invoked .bind()/.call()/.apply()

[DexterHaxxor]

Bug Report

🔎 Search Terms

function type inferrence, function apply function, function call function

🕗 Version & Regression Information

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

⏯ Playground Link

Playground link with relevant code

💻 Code

let f2 = function(this: number[]) {
    console.log(this)
}.bind([1, 2, 3]);
// ^^ works fine

let f1 = function() {
    console.log(this)
// ^^ 'this' implicitly has type 'any' because it does not have a type annotation.
}.bind([1, 2, 3]);

🙁 Actual behavior

Compiler shows an error: "'this' implicitly has type 'any' because it does not have a type annotation."

🙂 Expected behavior

The type of this to be correctly infered from the bind, call or apply call.

[DanielRosenwasser]

We do inference based on arguments of IIFEs, but that's because IIFEs are common. I've never seen this pattern in the wild. Is there a use-case for this?

[DexterHaxxor]

You need arguments (which is obviously not in arrow functions) but you want this to not change.