🔎 Search Terms

generator tnext yield type

🕗 Version & Regression Information

• This is the behavior in every version I tried between 5.0.4 ~ 6.0.2

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=6.0.2&filetype=ts#code/IYIwzgLgTsDGEAJYBthjAgggg3gXwChRIZ4lV0EAhXQggUwA8AHAeykQDMBXAO3gCWrXggBUnADzAETCPV4ATDJgA0CEDMZzFGKgD4AFDADuALgQBxefRgR2UhAB91a3vQBuN19wC2IG3oAlOZWbrb20s4grh5eCLy+-lB6uAQI6UjCkAiMCAC8CCYAdG5aBoFF7sDI3PQA3GkZApwIBrkCvJDA-PSsLZiBtDLIYPQIEAAWUKzG8fSzAKJQ01DlDRkIyPSIrNwQzHvmker5OesZnOytdXWDOI0b6bBZiAKnAJ4C9MgKCLv7e3Ojz+ewOiAKxVKEAMAgqVRq9QeCEIhCAA

💻 Code

abstract class A {}
abstract class B {}

export function *f<a extends A, b extends B>(raw: Generator<a | b, never, number>): Generator<a | b, never, number> {
    const x = raw.next().value;
    if (x instanceof A) {} else throw new Error();
    let output: a | b = x;
    for (;;) {
        const i = yield output;
        output = raw.next(i).value;
    }
}

🙁 Actual behavior

The type of i should be infered as number because the function signature is explicitly declared.

🙂 Expected behavior

'i' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.

Additional information about the issue

No response