testAsync

The test() function is the value imported from the test module. Each invocation of this function results in reporting the test to the TestsStream.

The TestContext object passed to the fn argument can be used to perform actions related to the current test. Examples include skipping the test, adding additional diagnostic information, or creating subtests.

test() returns a Promise that fulfills once the test completes. if test() is called within a suite, it fulfills immediately. The return value can usually be discarded for top level tests. However, the return value from subtests should be used to prevent the parent test from finishing first and cancelling the subtest as shown in the following example.

test('top level test', async (t) => {
  // The setTimeout() in the following subtest would cause it to outlive its
  // parent test if 'await' is removed on the next line. Once the parent test
  // completes, it will cancel any outstanding subtests.
  await t.test('longer running subtest', async (t) => {
    return new Promise((resolve, reject) => {
      setTimeout(resolve, 1000);
    });
  });
});

The timeout option can be used to fail the test if it takes longer than timeout milliseconds to complete. However, it is not a reliable mechanism for canceling tests because a running test might block the application thread and thus prevent the scheduled cancellation.

Parameters

The node:test/reporters module exposes the builtin-reporters for node:test. To access it:

import test from 'node:test/reporters';

This module is only available under the node: scheme. The following will not work:

import test from 'node:test/reporters';

See also