ts-r
  • Sound mode S-10, pre-alpha
  • Design record 0007, Accepted

TSR1002

'void' discards a promise that can reject. Attach '.catch' first: 'void {0}.catch(...)'.

'void' discards a promise that can still reject. Attach a handler first: void p.catch(...).

Rule S-10: No floating promises (level: strict). Reported by ts-r-check and ts-r-lsp in files that opt in to sound mode. See Sound mode.

What it means

void p hides a promise from the type checker but not its rejection. In sound and strict files void is allowed only on a handled chain.

Example

Spec case from design record 0007 (checked by the record's case harness, not by this site's build)
// void hides the promise but not its rejection.
async function save(x: string): Promise<void> {
  console.log(x);
}
void save("a"); // @expect TSR1002
export {};

How to fix

  • Handle the rejection before discarding: void save(user).catch(report).
  • Or await the promise.

Sound mode is defined in design record 0007 (accepted 2026-10-15).