BMAD-METHOD/.claude/rules/jest-unit-testing-cursorrules-prompt-file

Jest Unit Testing Prompt

A specialized .cursorrules prompt for creating comprehensive unit tests using Jest with TypeScript support.

What You Can Build

• Unit Test Suites: Focused tests for critical business logic and utility functions
• Mock-Based Testing: Tests that properly isolate code from external dependencies
• Data-Driven Tests: Tests that validate functionality across multiple data scenarios
• TypeScript Testing: Strongly-typed tests with proper interface definitions
• Edge Case Coverage: Tests that handle unexpected inputs and boundary conditions

Benefits

• Proper Dependency Isolation: Consistent mocking of dependencies before imports
• Complete TypeScript Support: Full type safety for tested functions and mocked dependencies
• Comprehensive Test Coverage: Focus on business logic with various data scenarios
• Organized Test Structure: Logical grouping of tests in descriptive describe blocks
• Edge Case Detection: Testing for null, undefined, and unexpected types that often cause bugs
• Maintainable Test Suite: Limited number of focused tests per file for better maintainability

Synopsis

This prompt helps developers create high-quality unit tests with Jest that focus on critical functionality while ensuring proper mocking of dependencies, comprehensive data scenarios, and edge case coverage.

Overview of .cursorrules Prompt

The .cursorrules prompt guides developers in creating effective unit tests using Jest with these key elements:

• TypeScript Detection: Automatically detects and adapts to TypeScript usage in the project
• Dependency Mocking: Guidelines for properly mocking dependencies before imports using Jest's mocking functions
• Best Practices: Eight essential practices for unit testing, including critical functionality focus, data scenarios, and edge cases
• Example Test Patterns: Provides detailed examples of unit tests in both JavaScript and TypeScript with proper structure
• Maintainable Approach: Focus on writing a limited number of high-value tests per file
• Test Organization: Structure tests using describe/it blocks with descriptive names
• AAA Pattern: Examples using the Arrange-Act-Assert pattern for clear test structure