jest.config.js

/** @type {import('jest').Config} */
export default {
  // Test environment
  testEnvironment: 'node',
  
  // TypeScript support
  preset: 'ts-jest/presets/default-esm',
  extensionsToTreatAsEsm: ['.ts'],
  
  // Module resolution
  moduleNameMapping: {
    '^(\\.{1,2}/.*)\\.js$': '$1',
  },
  
  // Test file patterns
  testMatch: [
    '**/tests/**/*.test.ts',
    '**/tests/**/*.spec.ts'
  ],
  
  // Coverage configuration
  collectCoverage: false, // Enable only when needed
  collectCoverageFrom: [
    'src/**/*.ts',
    '!src/**/*.d.ts',
    '!src/types/**',
    '!src/**/*.test.ts',
    '!src/**/*.spec.ts'
  ],
  
  coverageDirectory: 'coverage',
  coverageReporters: [
    'text',
    'text-summary',
    'html',
    'lcov'
  ],
  
  // Coverage thresholds
  coverageThreshold: {
    global: {
      branches: 90,
      functions: 90,
      lines: 90,
      statements: 90
    }
  },
  
  // Setup files
  setupFilesAfterEnv: ['<rootDir>/tests/setup.ts'],
  
  // Test timeout
  testTimeout: 30000,
  
  // Transform configuration
  transform: {
    '^.+\\.ts$': ['ts-jest', {
      useESM: true,
      tsconfig: {
        module: 'esnext'
      }
    }]
  },
  
  // Module file extensions
  moduleFileExtensions: ['ts', 'js', 'json'],
  
  // Ignore patterns
  testPathIgnorePatterns: [
    '/node_modules/',
    '/build/',
    '/dist/'
  ],
  
  // Clear mocks between tests
  clearMocks: true,
  
  // Verbose output
  verbose: true,
  
  // Error handling
  errorOnDeprecated: true,
  
  // Global variables
  globals: {
    'ts-jest': {
      useESM: true
    }
  }
};