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,

  // An array of glob patterns indicating a set of files for which coverage information should be collected
  collectCoverageFrom: ['src/app/**'],

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

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

  // The glob patterns Jest uses to detect test files
  testMatch: ['**/src/**/*.spec.ts'],

  transform: {
    '^.+\\.ts$': 'ts-jest'
  },
  moduleFileExtensions: ['ts', 'js', 'json', 'node']
}