jest.config.js

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

module.exports = {
  // All imported modules in your tests should be mocked automatically
  automock: false,

  // 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: ['<rootDir>/lib/*.js'],

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

  // An array of regexp pattern strings used to skip coverage collection
  coveragePathIgnorePatterns: [
    '/node_modules/',
    '<rootDir>/lib/constants.js',
    '<rootDir>/lib/typedefs.js'
  ],

  // A list of reporter names that Jest uses when writing coverage reports
  // coverageReporters: [
  //   "json",
  //   "text",
  //   "lcov",
  //   "clover"
  // ],

  // An array of file extensions your modules use
  moduleFileExtensions: ['js'],

  // Automatically reset mock state between every test
  resetMocks: false,

  // Automatically restore mock state between every test
  restoreMocks: false,

  // A list of paths to directories that Jest should use to search for files in
  roots: ['<rootDir>/tests/', '<rootDir>/lib/'],

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

  // The glob patterns Jest uses to detect test files
  testMatch: ['**/?(*.)+(spec|test).[tj]s?(x)'],

  // An array of regexp pattern strings that are matched against all modules before the module loader will automatically return a mock for them
  unmockedModulePathPatterns: []
};