How do you use Node.js's built-in test runner (node:test) without external libraries?

Short answer

The node:test module and node:assert provide a fast, built-in test environment with test, describe, and it functions.

Explanation

Modern Node.js provides an official test runner with concurrency, code coverage, and mocking, so you do not need to install external libraries.

Code example

import { test } from "node:test";
import assert from "node:assert/strict";
test("basic", () => assert.equal(1, 1));

Common mistakes

• Installing large external packages for simple tests when the built-in runner is sufficient.

Follow-up questions

• Why is the node: prefix useful when importing built-in modules such as node:fs and node:path?

Sources

• Node.js docs — Test runner