jest.config.js

const nextJest = require('next/jest')

const createJestConfig = nextJest({
  // Provide the path to your Next.js app to load next.config.js and .env files
  dir: './',
})

// Add any custom config to be passed to Jest
const customJestConfig = {
  // Setup files
  setupFilesAfterEnv: ['<rootDir>/test/setup.ts'],
  
  // Test environments
  testEnvironment: 'jsdom',
  
  // Module name mapping for path aliases
  moduleNameMapper: {
    '^@/(.*)$': '<rootDir>/$1',
    '^@/lib/(.*)$': '<rootDir>/lib/$1',
    '^@/components/(.*)$': '<rootDir>/components/$1',
    '^@/app/(.*)$': '<rootDir>/app/$1',
  },
  
  // Test file patterns
  testMatch: [
    '<rootDir>/test/**/*.test.{js,jsx,ts,tsx}',
    '<rootDir>/**/__tests__/**/*.{js,jsx,ts,tsx}',
  ],
  
  // Ignore patterns
  testPathIgnorePatterns: ['<rootDir>/.next/', '<rootDir>/node_modules/'],
  
  // Coverage configuration
  collectCoverage: false,
  collectCoverageFrom: [
    'lib/**/*.{js,ts,tsx}',
    'app/**/*.{js,ts,tsx}',
    'components/**/*.{js,ts,tsx}',
    '!**/*.d.ts',
    '!**/node_modules/**',
    '!**/.next/**',
    '!**/coverage/**',
    '!**/*.config.{js,ts}',
  ],
  coverageReporters: ['text', 'lcov', 'html'],
  coverageDirectory: 'coverage',
  coverageThreshold: {
    global: {
      branches: 75,
      functions: 80,
      lines: 80,
      statements: 80,
    },
  },
  
  // Transform configuration
  transform: {
    '^.+\\.(js|jsx|ts|tsx)$': ['ts-jest', {
      tsconfig: 'tsconfig.json',
    }],
  },
  
  // Module file extensions
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json'],
  
  // Test timeout
  testTimeout: 10000,
  
  // Verbose output
  verbose: true,
  
  // Globals for different test types
  globals: {
    'ts-jest': {
      tsconfig: 'tsconfig.json',
    },
  },
}

// createJestConfig is exported this way to ensure that next/jest can load the Next.js config which is async
module.exports = createJestConfig(customJestConfig)