Node.js Test Runner
Below is a clear and complete guide on the Node.js Test Runner, introduced officially in Node.js v18+ as a built-in testing framework — no external packages required.
🚀 Node.js Test Runner (Built-in Testing Framework)
Node.js now includes a native test runner so you can write tests without Jest, Mocha, or any other library.
Import from:
Or using ES Modules:
⭐ 1. Create Your First Node.js Test
📁 sum.js
📁 sum.test.js
Run test:
⭐ 2. Asynchronous Tests
Supports async/await:
⭐ 3. Test Suites (Subtests)
Use nested tests:
⭐ 4. Running a Specific Test File
⭐ 5. Using Test Hooks (Before / After)
⭐ 6. Skipping Tests
⭐ 7. Todo Tests
⭐ 8. Mocking & Spying (built-in)
Node.js has its own mocking API:
⭐ 9. Test Reporter Options
To see full output:
Available reporters:
-
tap -
spec -
json -
junit
Example:
⭐ 10. Assertions API
Node.js Test Runner uses node:assert, including:
Example:
⭐ 11. Testing ES Modules
Run:
⭐ 12. Folder Structure
Node automatically detects files named:
-
*.test.js -
test-*.js -
inside
/testfolder
⭐ 13. Comparison: Node Test Runner vs Jest vs Mocha
| Feature | Node Test Runner | Jest | Mocha |
|---|---|---|---|
| Built-in | ✔ Yes | ❌ | ❌ |
| Zero config | ✔ | ✔ | ❌ |
| Mocking | ✔ built-in | ✔ | ❌ (need Sinon) |
| Snapshot Testing | ❌ | ✔ | ❌ |
| API Testing | ✔ (with fetch + assert) | ✔ | ✔ |
| Speed | Very Fast | Fast | Slower |
| Best For | Backend Node apps | Full-stack apps | Enterprise backend |
🎯 When to Use Node.js Test Runner?
Use it when:
✔ You want minimal dependencies
✔ You want very fast tests
✔ You work mostly on backend / APIs
✔ You prefer native Node.js tools
✔ You don’t need React/Jest-specific features
