bun-test

Files (4)

• SKILL.md
• examples.md · references/
• jest-migration.md · references/
• mocking.md · references/

SKILL.md (first lines)

---
name: bun-test
description: Configure Bun's built-in test runner with Jest-compatible APIs. Use when setting up testing infrastructure, writing unit/integration/snapshot tests, migrating from Jest, or configuring test coverage. 3-10x faster than Jest.
compatibility: Requires Bun 1.0+
allowed-tools: ["Bash", "Write", "Read"]
metadata:
  author: dale
  category: bun-runtime
  tags: [bun, testing, jest, unit-tests, tdd]
---

# Bun Test Configuration

Set up Bun's built-in test runner with Jest-compatible APIs and significantly faster execution (3-10x faster than Jest).

## Quick Reference

For detailed patterns, see:
- **Jest Migration**: [jest-migration.md](references/jest-migration.md) - Complete Jest to Bun migration guide
- **Mocking**: [mocking.md](references/mocking.md) - Mock functions, spies, module mocking
- **Examples**: [examples.md](references/examples.md) - Test patterns for APIs, databases, async code

## Core Workflow

### 1. Check Prerequisites

```bash
# Verify Bun installation
bun --version

# Check if project exists
ls -la package.json
```

### 2. Determine Testing Needs

Ask the user what type of testing they need:

- **Unit Testing**: Test individual functions and modules
- **Integration Testing**: Test component interactions
- **API Testing**: Test HTTP endpoints
- **Snapshot Testing**: Test output consistency

### 3. Create Test Directory Structure

```bash
# Create test directories
mkdir -p tests/{unit,integration,fixtures}
```

Recommended structure:
```
project/
├── src/
│   ├── utils.ts
│   └── components/
├── tests/
│   ├── unit/              # Unit tests
│   ├── integration/       # Integration tests
│   ├── fixtures/          # Test data
│   └── setup.ts          # Global setup
├── package.json
└── bunfig.toml           # Test configuration
```

### 4. Configure Bun Test

Create `bunfig.toml` in project root:

```toml
[test]
# Preload files before running tests
preload = ["./tests/setup.ts"]

# Code coverage
coverage = true
coverageDir = "coverage"
coverageThreshold = 80

# Timeouts (in milliseconds)
timeout = 5000

# Bail after first failure
bail = false
```

### 5. Create Test Setup File

Create `tests/setup.ts`:

```typescript
import { beforeAll, afterAll, beforeEach, afterEach } from "bun:test";

// Global test setup
beforeAll(() => {
  console.log("🧪 Starting test suite");
  process.env.NODE_ENV = "test";
});

afterAll(() => {
  console.log("✅ Test suite complete");
});

// Reset mocks before each test
beforeEach(() => {
  // Clear mock state
});

afterEach(() => {
  // Cleanup after each test
});

// Global test utilities
globalThis.testHelpers = {
  wait: (ms: number) => new Promise(resolve => setTimeout(resolve, ms)),
};
```

### 6. Write First Test

From involvex/syncstuff, MIT.

More from involvex/syncstuff