Testing & DebuggingLesson 77Free preview

Node Test Runner

This lesson is part of Node.js · All levels

Summary

This lesson discusses the built-in test runner Node.js, which is the node:test module available since Node 18. You can write a test with require('node:test') and an assertion with node:assert without additional dependencies. Also supports --testing on CLI, mocking, subtesting, and synchronous and async writing.

Key points

Run the test with the node --test or node --test '*.test.js'.
Node:test provides test(), describe(), it(), beforeEach(), and other hooks.
Assertion uses node:assert or node:assert/strict (strictEqual, deepStrictEqual, rejects).
Test async is written with async/await; a failure promise will be considered a failed test.
Support mocking (mock.method, timers) and coverage through --experimental-test-coverage.

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