test

To enable built-in Node.js APIs and polyfills, add the nodejs_compat compatibility flag to your Wrangler configuration file. This also enables nodejs_compat_v2 as long as your compatibility date is 2024-09-23 or later. Learn more about the Node.js compatibility flag and v2.

MockTracker

The MockTracker API in Node.js provides a means of tracking and managing mock objects in a test environment.

import { mock } from 'node:test';

const fn = mock.fn();
fn(1,2,3);  // does nothing... but

console.log(fn.mock.callCount());  // Records how many times it was called
console.log(fn.mock.calls[0].arguments));  // Recoreds the arguments that were passed each call

The full MockTracker API is documented in the Node.js documentation for MockTracker ↗.

The Workers implementation of MockTracker currently does not include an implementation of the Node.js mock timers API ↗.