jest.conf.js

const tsconfig = require('../../../tsconfig.json');

module.exports = {
  transform: {
    '^.+\\.tsx?$': 'ts-jest'
  },
  rootDir: '../../../',
  testURL: 'http://localhost/',
  cacheDirectory: '<rootDir>/target/jest-cache',
  coverageDirectory: '<rootDir>/target/test-results/',
  testMatch: ['<rootDir>/src/test/javascript/spec/**/@(*.)@(spec.ts?(x))'],
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
  coveragePathIgnorePatterns: [
    '<rootDir>/src/test/javascript'
  ],
  moduleNameMapper: mapTypescriptAliasToJestAlias({
    '\\.(css|scss)$': 'identity-obj-proxy'
  }),
  reporters: [
    'default',
    [ 'jest-junit', { outputDirectory: './target/test-results/', outputName: 'TESTS-results-jest.xml' } ]
  ],
  testResultsProcessor: 'jest-sonar-reporter',
  testPathIgnorePatterns: [
    '<rootDir>/node_modules/'
  ],
  setupFiles: [
    '<rootDir>/src/test/javascript/spec/enzyme-setup.ts',
    '<rootDir>/src/test/javascript/spec/storage-mock.ts'
  ],
  snapshotSerializers: ['enzyme-to-json/serializer'],
  globals: {
    'ts-jest': {
      tsConfig: './tsconfig.test.json',
      diagnostics: false
    }
  }
};

function mapTypescriptAliasToJestAlias(alias = {}) {
    const jestAliases = { ...alias };
    if (!tsconfig.compilerOptions.paths) {
      return jestAliases;
    }
    Object.entries(tsconfig.compilerOptions.paths)
      .filter(([key, value]) => {
        // use Typescript alias in Jest only if this has value
        if (value.length) {
          return true;
        }
        return false;
      })
      .map(([key, value]) => {
        // if Typescript alias ends with /* then in Jest:
        // - alias key must end with /(.*)
        // - alias value must end with /$1
        const regexToReplace = /(.*)\/\*$/;
        const aliasKey = key.replace(regexToReplace, '$1/(.*)');
        const aliasValue = value[0].replace(regexToReplace, '$1/$$1');
        return [aliasKey, `<rootDir>/${aliasValue}`];
      })
      .reduce((aliases, [key, value]) => {
        aliases[key] = value;
        return aliases;
      }, jestAliases);
    return jestAliases;
  }