Cannot auto indicate return type

[loynoir]

Bug Report

🔎 Search Terms

🕗 Version & Regression Information

• This is a crash
• This changed between versions Version 4.6.2__ and _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________
• I was unable to test this on prior versions because _______

⏯ Playground Link

Playground link with relevant code

💻 Code

async function reproduce3<
  T extends (...args: any[]) => Promise<any>
>(fn: T) {
  const ret: Awaited<ReturnType<T>> = await fn(1, 2, 3);
  return ret;
}

🙁 Actual behavior

/**
 * const x3: any
 */
const x3 = await reproduce3(async () => 123 as const);

🙂 Expected behavior

/**
 * const x3: 123
 */
const x3 = await reproduce3(async () => 123 as const);

Other OK examples as comparison

Wrap into object

async function reproduce<T extends (...args: any[]) => Promise<any>>(fn: T) {
  const ret: {
    val: Awaited<ReturnType<T>>;
  } = { val: await fn(1, 2, 3) };
  return ret;
}

/**
 * const x: { val: 123 }
 */
const x = await reproduce(async () => 123 as const);

Explict

async function reproduce2<T extends (...args: any[]) => Promise<any>>(
  fn: T
): Promise<Awaited<ReturnType<T>>> {
  const ret = await fn(1, 2, 3);
  return ret;
}

/**
 * const x2: 123
 */
const x2 = await reproduce2(async () => 123 as const);