mocha done() called multiple times: how to fix

TL;DR

Something invoked the completion callback twice: an event firing twice, or both a promise resolving and done() being called. Pick one completion style per test and guard the other path.

Error

Error: done() called multiple times in test ["saves the record"]

Steps

1. Find the test and list every path that calls done() or resolves. Expected: two paths visible.
2. Common case: both .then(() => done()) and a done() in the callback. Remove one. Expected: single completion.
3. If an event emitter fires twice, guard: let called = false; ... if (!called) { called = true; done(); }. Expected: idempotent completion.
4. Prefer returning the promise instead of done() for promise tests. Expected: Mocha handles completion; no double-call possible.
5. Re-run. Expected: green.

When to use

• The exact error done() called multiple times.
• Callback-style async tests.

When not to use

• Promise-returning tests (return the promise; drop done()).
• Async/await tests (no done() at all).

Tool compatibility

• Mocha 9 through 11.

Variant phrasings

Mocha done called twice

Same error; two completion paths.

done() invoked multiple times with async

Mixing styles; pick one.

Why it happens

Mocha counts completions. Callbacks, events, and promises each offer a completion path, and using two fires twice.

Edge cases

• done passed into a helper that also returns a promise is the classic trap.
• Timeouts can fire done after the test already completed; clear timers.
• Prefer async/await for new tests; done() is legacy.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_7tChTzyxPWpgIPNKK-X91Q