jest.config.js

/*
 * For a detailed explanation regarding each configuration property, visit:
 * https://jestjs.io/docs/configuration
 */

module.exports = {
  // Automatically clear mock calls and instances between every test
  clearMocks: true,
  // Indicates whether the coverage information should be collected while executing the test
  collectCoverage: true,
  // An array of glob patterns indicating a set of files for which coverage information should be collected
  collectCoverageFrom: [
    '**/*.{js,jsx,ts,tsx}',
    '!**/*.d.ts',
    '!**/node_modules/**',
    '!<rootDir>/out/**',
    '!<rootDir>/.next/**',
    '!<rootDir>/*.config.js',
    '!<rootDir>/coverage/**',
  ],
  // The directory where Jest should output its coverage files
  coverageDirectory: "coverage",
  // A map from regular expressions to module names or to arrays of module names that allow to stub out resources with a single module
  moduleNameMapper: {
    // Handle CSS imports (with CSS modules)
    // https://jestjs.io/docs/webpack#mocking-css-modules
    '^.+\\.module\\.(css|sass|scss)$': 'identity-obj-proxy',

    // Handle CSS imports (without CSS modules)
    '^.+\\.(css|sass|scss)$': '<rootDir>/__mocks__/styleMock.js',

    // Handle image imports
    // https://jestjs.io/docs/webpack#handling-static-assets
    '^.+\\.(jpg|jpeg|png|gif|webp|svg)$': `<rootDir>/__mocks__/fileMock.js`,
  },

  // A list of paths to modules that run some code to configure or set up the testing framework before each test
  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
  testPathIgnorePatterns: ['<rootDir>/node_modules/', '<rootDir>/.next/'],
  // The test environment that will be used for testing
  testEnvironment: "jsdom",
  // A map from regular expressions to paths to transformers
  transform: {
    // // Use babel-jest to transpile tests with the next/babel preset
    // // https://jestjs.io/docs/configuration#transform-objectstring-pathtotransformer--pathtotransformer-object
    '^.+\\.(js|jsx|ts|tsx)$': ['babel-jest', { presets: ['next/babel'] }],
  },
  // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
  transformIgnorePatterns: [
    // `export` がシンタックスエラーになるので `node_modules` を一時的に除外する
    // "/node_modules/",
    '^.+\\.module\\.(css|sass|scss)$',
  ],
};