jest.config.ts

import type { Config } from '@jest/types';
import nextJest from 'next/jest';

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

// Add any custom config to be passed to Jest
const customJestConfig: Config.InitialOptions = {
  collectCoverageFrom: [
    '**/*.{js,jsx,ts,tsx}',
    '!**/*.d.ts',
    '!**/node_modules/**',
  ],
  coveragePathIgnorePatterns: ['/node_modules/'],
  // extensionsToTreatAsEsm: ['.ts'],
  globals: {
    'ts-jest': {
      useESM: true,
    },
  },
  testMatch: ['tests/**/*.+(ts|tsx|js)', '**/?(*.)+(spec|test).+(ts|tsx|js)'],
  roots: ['<rootDir>/src', '<rootDir>/tests'],
  preset: 'ts-jest',
  transform: {
    '^.+\\.(js|jsx|ts|tsx)$': [
      'ts-jest',
      { presets: ['next/babel', '@babel/preset-typescript'] },
    ],
  },
  transformIgnorePatterns: [
    '/node_modules/',
    '^.+\\.module\\.(css|sass|scss)$',
  ],
  testEnvironment: 'jsdom',
  testPathIgnorePatterns: ['<rootDir>/.next/', '<rootDir>/node_modules/'],
  moduleDirectories: ['node_modules', 'src'],
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node', 'cjs'],
  modulePaths: ['<rootDir>'],
  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
  moduleNameMapper: {
    // Handle module aliases (this will be automatically configured for you soon)
    '^@/components/(.*)$': '<rootDir>/components/$1',
    '\\.(scss|sass|css)$': 'identity-obj-proxy',
    '^(\\.{1,2}/.*)\\.js$': '$1',
    '^@/pages/(.*)$': '<rootDir>/pages/$1',
    '^csv-parse/sync': '<rootDir>/node_modules/csv-parse/dist/cjs/sync.cjs',
  },
  verbose: true,
};

// createJestConfig is exported this way to ensure that next/jest can load the Next.js config which is async
export default createJestConfig(customJestConfig);