plan

fun plan(count: Number)(source)

Used to set the number of assertions and subtests that are expected to run within the test. If the number of assertions and subtests that run does not match the expected count, the test will fail.

To make sure assertions are tracked, the assert functions on context.assert must be used, instead of importing from the node:assert module.

test('top level test', (t) => {
  t.plan(2);
  t.assert.ok('some relevant assertion here');
  t.test('subtest', () => {});
});

When working with asynchronous code, the plan function can be used to ensure that the correct number of assertions are run:

test('planning with streams', (t, done) => {
  function* generate() {
    yield 'a';
    yield 'b';
    yield 'c';
  }
  const expected = ['a', 'b', 'c'];
  t.plan(expected.length);
  const stream = Readable.from(generate());
  stream.on('data', (chunk) => {
    t.assert.strictEqual(chunk, expected.shift());
  });
  stream.on('end', () => {
    done();
  });
});

Since

v22.2.0