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

TypeScript Version: 3.5.1, 3.7.5, 3.8-Beta

Search Terms: async, await, loop, promise, variable assignment, implicitly has type any, referenced directly or indirectly in its own initializer.

Code

interface Foo {
    id : string,
}

declare function paginate(after: string|undefined): Promise<Foo[]>;

async function main() {
    let after: string | undefined = undefined;
    while (true) {
        const page = await paginate(after);
        for (const foo of page) {
            after = foo.id;
        }
    }   
}

Expected behavior:

Type checks successfully

Actual behavior:

Playground Link: Playground

Related Issues:

Similar to https://github.com/microsoft/TypeScript/issues/14428 , an already fixed issue.

Similar to https://github.com/microsoft/TypeScript/issues/36666 , but without destructuring; and my initial variable also has explicit type annotations (after : string|undefined)

---

Workaround

Just use an explicit type annotation,

const page : Foo[] = await paginate(after);

However, it is strange. It shouldn’t need the explicit type annotation because it can only possibly be Foo[].

[evenfrost]

Any update on this? Just faced this very error in the while loop.

[evenfrost]

Faced this again, found this thread again, realized that I had already commented on this a year ago.

Well, as I’m back here, any update on this? Removing the async/await stuff from this throws no error, so I believe it’s more like a bug than a design limitation.