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How to use validateExtensionsToTreatAsEsm method in Jest

Best JavaScript code snippet using jest

normalize.js

Source:normalize.js

...499        'Running all tests instead.'500    )501  );502};503function validateExtensionsToTreatAsEsm(extensionsToTreatAsEsm) {504  if (!extensionsToTreatAsEsm || extensionsToTreatAsEsm.length === 0) {505    return;506  }507  function printConfig(opts) {508    const string = opts.map(ext => `'${ext}'`).join(', ');509    return _chalk().default.bold(`extensionsToTreatAsEsm: [${string}]`);510  }511  const extensionWithoutDot = extensionsToTreatAsEsm.some(512    ext => !ext.startsWith('.')513  );514  if (extensionWithoutDot) {515    throw createConfigError(`  Option: ${printConfig(516      extensionsToTreatAsEsm517    )} includes a string that does not start with a period (${_chalk().default.bold(518      '.'519    )}).520  Please change your configuration to ${printConfig(521    extensionsToTreatAsEsm.map(ext => (ext.startsWith('.') ? ext : `.${ext}`))522  )}.`);523  }524  if (extensionsToTreatAsEsm.includes('.js')) {525    throw createConfigError(526      `  Option: ${printConfig(527        extensionsToTreatAsEsm528      )} includes ${_chalk().default.bold(529        "'.js'"530      )} which is always inferred based on ${_chalk().default.bold(531        'type'532      )} in its nearest ${_chalk().default.bold('package.json')}.`533    );534  }535  if (extensionsToTreatAsEsm.includes('.cjs')) {536    throw createConfigError(537      `  Option: ${printConfig(538        extensionsToTreatAsEsm539      )} includes ${_chalk().default.bold(540        "'.cjs'"541      )} which is always treated as CommonJS.`542    );543  }544  if (extensionsToTreatAsEsm.includes('.mjs')) {545    throw createConfigError(546      `  Option: ${printConfig(547        extensionsToTreatAsEsm548      )} includes ${_chalk().default.bold(549        "'.mjs'"550      )} which is always treated as an ECMAScript Module.`551    );552  }553}554async function normalize(555  initialOptions,556  argv,557  configPath,558  projectIndex = Infinity559) {560  var _options$haste, _argv$_;561  const {hasDeprecationWarnings} = (0, _jestValidate().validate)(562    initialOptions,563    {564      comment: _utils.DOCUMENTATION_NOTE,565      deprecatedConfig: _Deprecated.default,566      exampleConfig: _ValidConfig.default,567      recursiveDenylist: [568        'collectCoverageOnlyFrom', // 'coverageThreshold' allows to use 'global' and glob strings on the same569        // level, there's currently no way we can deal with such config570        'coverageThreshold',571        'globals',572        'moduleNameMapper',573        'testEnvironmentOptions',574        'transform'575      ]576    }577  );578  let options = normalizePreprocessor(579    normalizeReporters(580      normalizeMissingOptions(581        normalizeRootDir((0, _setFromArgv.default)(initialOptions, argv)),582        configPath,583        projectIndex584      )585    )586  );587  if (options.preset) {588    options = await setupPreset(options, options.preset);589  }590  if (!options.setupFilesAfterEnv) {591    options.setupFilesAfterEnv = [];592  }593  if (594    options.setupTestFrameworkScriptFile &&595    options.setupFilesAfterEnv.length > 0596  ) {597    throw createConfigError(`  Options: ${_chalk().default.bold(598      'setupTestFrameworkScriptFile'599    )} and ${_chalk().default.bold(600      'setupFilesAfterEnv'601    )} cannot be used together.602  Please change your configuration to only use ${_chalk().default.bold(603    'setupFilesAfterEnv'604  )}.`);605  }606  if (options.setupTestFrameworkScriptFile) {607    options.setupFilesAfterEnv.push(options.setupTestFrameworkScriptFile);608  }609  options.testEnvironment = (0, _jestResolve().resolveTestEnvironment)({610    requireResolveFunction: require.resolve,611    rootDir: options.rootDir,612    testEnvironment:613      options.testEnvironment ||614      require.resolve(_Defaults.default.testEnvironment)615  });616  if (!options.roots && options.testPathDirs) {617    options.roots = options.testPathDirs;618    delete options.testPathDirs;619  }620  if (!options.roots) {621    options.roots = [options.rootDir];622  }623  if (624    !options.testRunner ||625    options.testRunner === 'circus' ||626    options.testRunner === 'jest-circus'627  ) {628    options.testRunner = require.resolve('jest-circus/runner');629  } else if (options.testRunner === 'jasmine2') {630    options.testRunner = require.resolve('jest-jasmine2');631  }632  if (!options.coverageDirectory) {633    options.coverageDirectory = path().resolve(options.rootDir, 'coverage');634  }635  setupBabelJest(options); // TODO: Type this properly636  const newOptions = {..._Defaults.default};637  if (options.resolver) {638    newOptions.resolver = (0, _utils.resolve)(null, {639      filePath: options.resolver,640      key: 'resolver',641      rootDir: options.rootDir642    });643  }644  validateExtensionsToTreatAsEsm(options.extensionsToTreatAsEsm);645  if (options.watchman == null) {646    options.watchman = _Defaults.default.watchman;647  }648  const optionKeys = Object.keys(options);649  optionKeys.reduce((newOptions, key) => {650    // The resolver has been resolved separately; skip it651    if (key === 'resolver') {652      return newOptions;653    } // This is cheating, because it claims that all keys of InitialOptions are Required.654    // We only really know it's Required for oldOptions[key], not for oldOptions.someOtherKey,655    // so oldOptions[key] is the only way it should be used.656    const oldOptions = options;657    let value;658    switch (key) {...

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What is Jest Framework
Advantages of Jest - Jest has 3,898,000 GitHub repositories, as mentioned on its official website. Learn what makes Jest special and why Jest has gained popularity among the testing and developer community.
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Using Jest with NodeJS Project - Learn how to leverage Jest framework to automate testing using a NodeJS Project.
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Unit Testing with Jest - Step-by-step tutorial to help you execute unit testing with Jest framework.
Jest Basics - Learn about the most pivotal and basic features which makes Jest special.
Jest Parameterized Tests - Avoid code duplication and fasten automation testing with Jest using parameterized tests. Parameterization allows you to trigger the same test scenario over different test configurations by incorporating parameters.
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|it('check_object_of_Car', () => { expect(newCar()).toBeInstanceOf(Car); });| | :- |

Jest Hooks: Setup and Teardown - Learn how to set up conditions which needs to be followed by the test execution and incorporate a tear down function to free resources after the execution is complete.
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Jest FAQs(Frequently Asked Questions) - Explore the most commonly asked questions around Jest framework, with their answers.