bug(lib): Explicitly stating wrong return type of Promise.then without arguments results in no error #63244
Description
🔎 Search Terms
- silenced Promise resolution type mismatch
- Promise generic explicit no error
- no error when Promise type is specified explicitly
- generic inside optional argument
🕗 Version & Regression Information
TS v3.3.3 correctly detects the error, which is the earliest Playground version. All other Playground versions silence the error.
⏯ Playground Link
💻 Code
const test: Promise<string> = Promise.resolve(1).then();🙁 Actual behavior
No TypeScript errors.
🙂 Expected behavior
I expected a similar error to what TS v3.3.3 yields:
Type
Promise<number>is not assignable to typePromise<string>. Typenumberis not assignable to typestring.
Additional information about the issue
No response