Version

18.15.0 (also affects the userland "test" module in 16.16)

Platform

Darwin J1.local 22.3.0 Darwin Kernel Version 22.3.0: Mon Jan 30 20:38:37 PST 2023; root:xnu-8792.81.3~2/RELEASE_ARM64_T6000 arm64

Subsystem

test_harness

What steps will reproduce the bug?

const { describe, it } = require('node:test');
const assert = require('assert');
describe('thing', () => {
  it('subthing', async (t) => {
    // always throws "passed a callback but also returned a Promise"
    assert(true);
  });
});

CodeSandbox Demo

How often does it reproduce? Is there a required condition?

Always.

What is the expected behavior?

I expect the test to run.

What do you see instead?

If you remove the t argument, the test works, but with t present the test always throws with ERR_TEST_FAILURE and a message of passed a callback but also returned a Promise.

TAP version 13
# Subtest: thing
    # Subtest: subthing
    not ok 1 - subthing
      ---
      duration_ms: 0.248708
      failureType: 'callbackAndPromisePresent'
      error: 'passed a callback but also returned a Promise'
      code: 'ERR_TEST_FAILURE'
      stack: |-
        new Promise (<anonymous>)
        Array.map (<anonymous>)
        new Promise (<anonymous>)
      ...
    1..1
not ok 1 - thing
  ---
  duration_ms: 1.341708
  failureType: 'subtestsFailed'
  error: '1 subtest failed'
  code: 'ERR_TEST_FAILURE'
  ...

Additional information

I think this might be an off by one error? If I remove the - 1 from this line, the test works as expected.