Node.js v18 introduces test runner support. This currently experimental feature gives developers the benefits of a structured test harness for their code without having to install a third party test framework, like Mocha or Jest, as a dependency. Using the test runner produces [TAP] output.
The [online reference] provides the most up-to-date, authoritative reference and have plenty of good testing examples. However, there are a few points that might not be immediately obvious from the reference, so those are highlighted here.