How to use loadBabelOptions method in Jest

Best JavaScript code snippet using jest

index.js

Source:index.js

...168  );169  assertLoadedBabelConfig(babelConfig, cwd, filename);170  return babelConfig;171}172function loadBabelOptions(173  cwd,174  filename,175  transformOptions,176  jestTransformOptions177) {178  const {options} = loadBabelConfig(cwd, filename, transformOptions);179  return addIstanbulInstrumentation(options, jestTransformOptions);180}181async function loadBabelOptionsAsync(182  cwd,183  filename,184  transformOptions,185  jestTransformOptions186) {187  const {options} = await loadBabelConfigAsync(cwd, filename, transformOptions);188  return addIstanbulInstrumentation(options, jestTransformOptions);189}190const createTransformer = userOptions => {191  var _inputOptions$plugins, _inputOptions$presets;192  const inputOptions =193    userOptions !== null && userOptions !== void 0 ? userOptions : {};194  const options = {195    ...inputOptions,196    caller: {197      name: 'babel-jest',198      supportsDynamicImport: false,199      supportsExportNamespaceFrom: false,200      supportsStaticESM: false,201      supportsTopLevelAwait: false,202      ...inputOptions.caller203    },204    compact: false,205    plugins:206      (_inputOptions$plugins = inputOptions.plugins) !== null &&207      _inputOptions$plugins !== void 0208        ? _inputOptions$plugins209        : [],210    presets: ((_inputOptions$presets = inputOptions.presets) !== null &&211    _inputOptions$presets !== void 0212      ? _inputOptions$presets213      : []214    ).concat(jestPresetPath),215    sourceMaps: 'both'216  };217  function mergeBabelTransformOptions(filename, transformOptions) {218    var _transformOptions$sup,219      _transformOptions$sup2,220      _transformOptions$sup3,221      _transformOptions$sup4;222    const {cwd} = transformOptions.config; // `cwd` first to allow incoming options to override it223    return {224      cwd,225      ...options,226      caller: {227        ...options.caller,228        supportsDynamicImport:229          (_transformOptions$sup = transformOptions.supportsDynamicImport) !==230            null && _transformOptions$sup !== void 0231            ? _transformOptions$sup232            : options.caller.supportsDynamicImport,233        supportsExportNamespaceFrom:234          (_transformOptions$sup2 =235            transformOptions.supportsExportNamespaceFrom) !== null &&236          _transformOptions$sup2 !== void 0237            ? _transformOptions$sup2238            : options.caller.supportsExportNamespaceFrom,239        supportsStaticESM:240          (_transformOptions$sup3 = transformOptions.supportsStaticESM) !==241            null && _transformOptions$sup3 !== void 0242            ? _transformOptions$sup3243            : options.caller.supportsStaticESM,244        supportsTopLevelAwait:245          (_transformOptions$sup4 = transformOptions.supportsTopLevelAwait) !==246            null && _transformOptions$sup4 !== void 0247            ? _transformOptions$sup4248            : options.caller.supportsTopLevelAwait249      },250      filename251    };252  }253  return {254    canInstrument: true,255    getCacheKey(sourceText, sourcePath, transformOptions) {256      const babelOptions = loadBabelConfig(257        transformOptions.config.cwd,258        sourcePath,259        mergeBabelTransformOptions(sourcePath, transformOptions)260      );261      return getCacheKeyFromConfig(262        sourceText,263        sourcePath,264        babelOptions,265        transformOptions266      );267    },268    async getCacheKeyAsync(sourceText, sourcePath, transformOptions) {269      const babelOptions = await loadBabelConfigAsync(270        transformOptions.config.cwd,271        sourcePath,272        mergeBabelTransformOptions(sourcePath, transformOptions)273      );274      return getCacheKeyFromConfig(275        sourceText,276        sourcePath,277        babelOptions,278        transformOptions279      );280    },281    process(sourceText, sourcePath, transformOptions) {282      const babelOptions = loadBabelOptions(283        transformOptions.config.cwd,284        sourcePath,285        mergeBabelTransformOptions(sourcePath, transformOptions),286        transformOptions287      );288      const transformResult = (0, _core().transformSync)(289        sourceText,290        babelOptions291      );292      if (transformResult) {293        const {code, map} = transformResult;294        if (typeof code === 'string') {295          return {296            code,...

utils.js

Source:utils.js

...39        warn(`There was an error while compiling ${filePath} ${err}`)40    }41    return content42}43const getBabelOptions = function loadBabelOptions(filename, options = {}) {44    const opts = Object.assign(options, {45        caller: {46            name: 'vue-jest',47            supportsStaticESM: false48        },49        filename,50        sourceMaps: 'both'51    })52    return loadPartialConfig(opts).options53}54const getTsJestConfig = function getTsJestConfig(config) {55    const createTransformer = require('ts-jest').createTransformer56    const tr = createTransformer()57    const configSet = tr.configsFor(config)...

babel.js

Source:babel.js

2const babel = require('@babel/core')3const debug = require('debug')('packages-scripts:utils:babel')4const {defaultSourceRoot} = require('../options')5const here = p => path.resolve(__dirname, p)6function loadBabelOptions() {7  try {8    const loadedBabelOptions = babel.loadOptions(getLoadOptions())9    debug('loaded options with `babel.loadOptions()` %o', loadedBabelOptions)10    return loadedBabelOptions11  } catch (error) {12    debug('loaded options with `babel.loadOptions()` failed')13    return null14  }15}16function loadBabelConfig() {17  let loadedBabelConfig18  try {19    loadedBabelConfig = babel.loadPartialConfig(getLoadOptions())20  } catch (error) {21    if (error.code === 'BABEL_ROOT_NOT_FOUND') {22      debug('Not found root `babel.config.js` file.')23      return null24    }25    throw error26  }27  debug(28    'loaded babel configuration derived from user-defined babel configuration file %o',29    loadedBabelConfig,30  )31  const extendConfigs = []32  if (loadedBabelConfig.config) {33    debug(`Found project-wide configuration file: ${loadedBabelConfig.config}`)34    extendConfigs.push(loadedBabelConfig.config)35  }36  if (loadedBabelConfig.babelrc) {37    debug(38      `Found sub-package-wide configuration file: ${loadedBabelConfig.babelrc}`,39    )40    extendConfigs.push(loadedBabelConfig.babelrc)41  }42  // return loadedBabelConfig43  // if (extendConfigs.length > 0) {44  //   console.group('Use loaded options instead of built-in configuration')45  //   console.log()46  //   console.groupEnd()47  //   return loadedBabelConfig.options48  // }49  if (!loadedBabelConfig.babelrc && !loadedBabelConfig.config) {50    return null51  }52  return loadedBabelConfig53}54function getLoadOptions() {55  return {56    rootMode: 'upward',57    // TODO: å¦æä¸åå¨ src çè¯åºè¯¥å¦ä½å¤ç58    filename: path.join(process.cwd(), defaultSourceRoot),59  }60}61function isUsingBuiltInBabelConfig() {62  return !loadBabelConfig()63}64function getBuiltInBabelPreset() {65  return here('../config/babel-config.js')66}67function getGeneralPluginsUsed() {68  const loadedBabelOptions = loadBabelOptions()69  if (!loadedBabelOptions) return null70  return loadedBabelOptions.plugins71}72function isPluginUsed(pluginName) {73  const usedPlugins = getGeneralPluginsUsed()74  if (!usedPlugins) return false75  return usedPlugins.some(p => p.key.includes(pluginName))76}77exports.loadBabelConfig = loadBabelConfig78exports.getBuiltInBabelPreset = getBuiltInBabelPreset79exports.isUsingBuiltInBabelConfig = isUsingBuiltInBabelConfig80exports.getGeneralBabelPluginsUsed = getGeneralPluginsUsed...

Jest Testing Tutorial

LambdaTest’s Jest Testing Tutorial covers step-by-step guides around Jest with code examples to help you be proficient with the Jest framework. The Jest tutorial has chapters to help you learn right from the basics of Jest framework to code-based tutorials around testing react apps with Jest, perform snapshot testing, import ES modules and more.

Chapters

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.
Jest Installation - All the prerequisites and set up steps needed to help you start Jest automation testing.
Using Jest with NodeJS Project - Learn how to leverage Jest framework to automate testing using a NodeJS Project.
Writing First Test for Jest Framework - Get started with code-based tutorial to help you write and execute your first Jest framework testing script.
Jest Vocabulary - Learn the industry renowned and official jargons of the Jest framework by digging deep into the Jest vocabulary.
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.
Jest Matchers - Enforce assertions better with the help of matchers. Matchers help you compare the actual output with the expected one. Here is an example to see if the object is acquired from the correct class or not. -

|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.
Jest Code Coverage - Unsure there is no code left unchecked in your application. Jest gives a specific flag called --coverage to help you generate code coverage.
HTML Report Generation - Learn how to create a comprehensive HTML report based on your Jest test execution.
Testing React app using Jest Framework - Learn how to test your react web-application with Jest framework in this detailed Jest tutorial.
Test using LambdaTest cloud Selenium Grid - Run your Jest testing script over LambdaTest cloud-based platform and leverage parallel testing to help trim down your test execution time.
Snapshot Testing for React Front Ends - Capture screenshots of your react based web-application and compare them automatically for visual anomalies with the help of Jest tutorial.
Bonus: Import ES modules with Jest - ES modules are also known as ECMAScript modules. Learn how to best use them by importing in your Jest testing scripts.
Jest vs Mocha vs Jasmine - Learn the key differences between the most popular JavaScript-based testing frameworks i.e. Jest, Mocha, and Jasmine.
Jest FAQs(Frequently Asked Questions) - Explore the most commonly asked questions around Jest framework, with their answers.