Bun Test Runner

Bun includes a fast, Jest-compatible test runner. Write tests using familiar syntax without any configuration.

Basic Test Structure

Tests use describe, test/it, and expect:

Testing Functions

Test your functions thoroughly:

Async Tests

Test asynchronous code:

Test Matchers

Common matchers for assertions:

Test Organization

Organize tests with lifecycle hooks:

Exercise: Test Writer

Write tests for a simple calculator:

Exercise: Custom Matcher

Create a custom matcher for testing ranges: