Return types fail to emit for methods of anonymous plain objects

Bug Report

🔎 Search Terms

declaration emit this any

🕗 Version & Regression Information

• This is the behavior in every version I tried

⏯ Playground Link

Playground link with relevant code

💻 Code

export function test() {
  return {
    relyingOnThis() {
      return this;
    },
  };
}

// seen and recognized locally in TS files
test().relyingOnThis();

🙁 Actual behavior

// generated .d.ts
export declare function test(): {
    relyingOnThis(): any;
};

🙂 Expected behavior

Make this type to work in such contexts and emit that:

declare function test(): {
    relyingOnThis(): this; // currently reports `A 'this' type is available only in a non-static member of a class or interface.(2526)`
};

Or emit the content of the anonymous type there somehow (when possible, be cautious with circularities, generics etc):

declare const _type: {
    relyingOnThis(): typeof _type;
}

declare function test(): typeof _type

Or just emit a diagnostic that this isn't portable and that an explicit annotation is needed.

Start with the linked TypeScript Playground and the example in the issue, then inspect how declaration emit handles the anonymous object returned by test(). Determine a defined outcome for the this type, an expanded anonymous type, or a diagnostic, and verify that the generated .d.ts is correct without introducing portability or circularity problems.