jest.config.js

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

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,

  // The directory where Jest should output its coverage files
  coverageDirectory: 'coverage',

  // An array of directory names to be searched recursively up from the requiring module's location
  moduleDirectories: ['node_modules', '<rootDir>/src'],

  // A map from regular expressions to module names that allow to stub out resources with a single module
  moduleNameMapper: {
    '\\.(css|less)$': '<rootDir>/__mocks__/styleMock.js',
    '\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$':
      '<rootDir>/__mocks__/fileMock.js',
    '@app/(.*)': '<rootDir>/src/app/$1'
  },

  // A preset that is used as a base for Jest's configuration
  preset: 'ts-jest/presets/js-with-ts',

  // The path to a module that runs some code to configure or set up the testing framework before each test
  setupFilesAfterEnv: ['<rootDir>/test-setup.js'],

  // The test environment that will be used for testing.
  testEnvironment: 'jsdom',

  // A list of paths to snapshot serializer modules Jest should use for snapshot testing
  snapshotSerializers: ['enzyme-to-json/serializer'],

  // Make tests pass
  transformIgnorePatterns: ['/node_modules/(?!(react-syntax-highlighter)/)']
};