Mocking Pattern

Mock dependencies effectively using Vitest mock functions, module mocking, timer control, MSW for HTTP requests, and Prisma mocking.

What's Included#

• Mock functions with return values, implementations, and call tracking
• Module mocking for imports with full and partial mock support
• Spy on methods without replacing the original implementation
• Timer mocking for debounce, setTimeout, and Date-dependent code
• MSW (Mock Service Worker) for realistic HTTP request interception
• Prisma client mocking with vitest-mock-extended
• Next.js module mocks for navigation, headers, and cache

Usage#

Via CLI#

Via AI Assistant#

Ask your AI assistant:

• "Use the mocking pattern from Bootspring"
• "Apply the Bootspring mocking pattern to my project"

Key Considerations#

• Mock at the boundary by replacing external services, not internal logic
• Clear mocks between tests with vi.clearAllMocks() to prevent state leakage
• Use MSW for HTTP mocking as it is more realistic than mocking fetch directly
• Prefer spying over mocking when you only need to observe behavior
• Keep mock implementations simple and clearly document what they return

Related Patterns#

• Vitest - Test runner setup
• Unit Testing - Unit testing patterns
• Fixtures - Test data management
• Integration Testing - Integration tests