Jest testing

Jest Testing Skill

Overview

This skill provides expert-level capabilities for Jest-based testing, enabling comprehensive unit testing, snapshot testing, and integration with React Testing Library.

Capabilities

Test Execution

• Configure Jest for various project types (Node, React, TypeScript)
• Execute tests with coverage collection
• Parallel test execution configuration
• Watch mode and selective test running

Unit Testing

• Write unit tests with proper mocking
• Configure custom matchers and test utilities
• Mock module resolution and timer handling
• Handle async testing patterns

Snapshot Testing

• Configure and manage snapshot tests
• Handle snapshot updates and reviews
• Implement inline snapshots

Coverage Analysis

• Coverage report generation and analysis
• Configure coverage thresholds
• Identify uncovered code paths

React Integration

• Integration with React Testing Library
• Component testing patterns
• Hook testing utilities

Target Processes

• automation-framework.js - Test framework setup
• mutation-testing.js - Test quality assessment
• continuous-testing.js - CI/CD integration
• shift-left-testing.js - Early testing integration

Dependencies

• jest - Test runner
• @testing-library/react - React testing utilities
• ts-jest - TypeScript support (optional)

Usage Example

{
  kind: 'skill',
  skill: {
    name: 'jest-testing',
    context: {
      action: 'execute-tests',
      testPath: 'src/**/*.test.ts',
      coverage: true,
      coverageThreshold: {
        global: { branches: 80, functions: 80, lines: 80 }
      }
    }
  }
}

Configuration

The skill respects jest.config.js or jest.config.ts in the project root and can override settings as needed.