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

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.

リンクされた TypeScript Playground の再現例から始め、即時に呼び出される bind、call、apply を使って、型注釈ありの関数と型注釈なしの関数を比較します。これらの呼び出しに対するコンパイラーの this 推論の扱いを追跡します。型注釈なしの例が implicit-any エラーなしでバインドされた配列型を推論し、既存の動作を維持できれば完了です。