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How to use createScriptTransformer method in Jest

Best JavaScript code snippet using jest

ScriptTransformer.js

Source:ScriptTransformer.js

...768    return this._config.transform.length !== 0 && !isIgnored;769  }770} // TODO: do we need to define the generics twice?771async function createTranspilingRequire(config) {772  const transformer = await createScriptTransformer(config);773  return async function requireAndTranspileModule(774    resolverPath,775    applyInteropRequireDefault = false776  ) {777    const transpiledModule = await transformer.requireAndTranspileModule(778      resolverPath,779      () => {},780      {781        applyInteropRequireDefault,782        instrument: false,783        supportsDynamicImport: false,784        // this might be true, depending on node version.785        supportsExportNamespaceFrom: false,786        supportsStaticESM: false,787        supportsTopLevelAwait: false788      }789    );790    return transpiledModule;791  };792}793const removeFile = path => {794  try {795    fs().unlinkSync(path);796  } catch {}797};798const stripShebang = content => {799  // If the file data starts with a shebang remove it. Leaves the empty line800  // to keep stack trace line numbers correct.801  if (content.startsWith('#!')) {802    return content.replace(/^#!.*/, '');803  } else {804    return content;805  }806};807/**808 * This is like `writeCacheFile` but with an additional sanity checksum. We809 * cannot use the same technique for source maps because we expose source map810 * cache file paths directly to callsites, with the expectation they can read811 * it right away. This is not a great system, because source map cache file812 * could get corrupted, out-of-sync, etc.813 */814function writeCodeCacheFile(cachePath, code) {815  const checksum = (0, _crypto().createHash)('md5').update(code).digest('hex');816  writeCacheFile(cachePath, checksum + '\n' + code);817}818/**819 * Read counterpart of `writeCodeCacheFile`. We verify that the content of the820 * file matches the checksum, in case some kind of corruption happened. This821 * could happen if an older version of `jest-runtime` writes non-atomically to822 * the same cache, for example.823 */824function readCodeCacheFile(cachePath) {825  const content = readCacheFile(cachePath);826  if (content == null) {827    return null;828  }829  const code = content.substring(33);830  const checksum = (0, _crypto().createHash)('md5').update(code).digest('hex');831  if (checksum === content.substring(0, 32)) {832    return code;833  }834  return null;835}836/**837 * Writing to the cache atomically relies on 'rename' being atomic on most838 * file systems. Doing atomic write reduces the risk of corruption by avoiding839 * two processes to write to the same file at the same time. It also reduces840 * the risk of reading a file that's being overwritten at the same time.841 */842const writeCacheFile = (cachePath, fileData) => {843  try {844    (0, _writeFileAtomic().sync)(cachePath, fileData, {845      encoding: 'utf8',846      fsync: false847    });848  } catch (e) {849    if (cacheWriteErrorSafeToIgnore(e, cachePath)) {850      return;851    }852    e.message =853      'jest: failed to cache transform results in: ' +854      cachePath +855      '\nFailure message: ' +856      e.message;857    removeFile(cachePath);858    throw e;859  }860};861/**862 * On Windows, renames are not atomic, leading to EPERM exceptions when two863 * processes attempt to rename to the same target file at the same time.864 * If the target file exists we can be reasonably sure another process has865 * legitimately won a cache write race and ignore the error.866 */867const cacheWriteErrorSafeToIgnore = (e, cachePath) =>868  process.platform === 'win32' &&869  e.code === 'EPERM' &&870  fs().existsSync(cachePath);871const readCacheFile = cachePath => {872  if (!fs().existsSync(cachePath)) {873    return null;874  }875  let fileData;876  try {877    fileData = fs().readFileSync(cachePath, 'utf8');878  } catch (e) {879    e.message =880      'jest: failed to read cache file: ' +881      cachePath +882      '\nFailure message: ' +883      e.message;884    removeFile(cachePath);885    throw e;886  }887  if (fileData == null) {888    // We must have somehow created the file but failed to write to it,889    // let's delete it and retry.890    removeFile(cachePath);891  }892  return fileData;893};894const getScriptCacheKey = (filename, instrument) => {895  const mtime = fs().statSync(filename).mtime;896  return filename + '_' + mtime.getTime() + (instrument ? '_instrumented' : '');897};898const calcIgnorePatternRegExp = config => {899  if (900    !config.transformIgnorePatterns ||901    config.transformIgnorePatterns.length === 0902  ) {903    return undefined;904  }905  return new RegExp(config.transformIgnorePatterns.join('|'));906};907const calcTransformRegExp = config => {908  if (!config.transform.length) {909    return undefined;910  }911  const transformRegexp = [];912  for (let i = 0; i < config.transform.length; i++) {913    transformRegexp.push([914      new RegExp(config.transform[i][0]),915      config.transform[i][1],916      config.transform[i][2]917    ]);918  }919  return transformRegexp;920};921function invariant(condition, message) {922  if (!condition) {923    throw new Error(message);924  }925}926function assertSyncTransformer(transformer, name) {927  invariant(name);928  invariant(929    typeof transformer.process === 'function',930    (0, _runtimeErrorsAndWarnings.makeInvalidSyncTransformerError)(name)931  );932}933async function createScriptTransformer(config, cacheFS = new Map()) {934  const transformer = new ScriptTransformer(config, cacheFS);935  await transformer.loadTransformers();936  return transformer;...

generateEmptyCoverage.js

Source:generateEmptyCoverage.js

1'use strict';2Object.defineProperty(exports, '__esModule', {3  value: true4});5exports.default = generateEmptyCoverage;6function fs() {7  const data = _interopRequireWildcard(require('graceful-fs'));8  fs = function () {9    return data;10  };11  return data;12}13function _istanbulLibCoverage() {14  const data = require('istanbul-lib-coverage');15  _istanbulLibCoverage = function () {16    return data;17  };18  return data;19}20function _istanbulLibInstrument() {21  const data = require('istanbul-lib-instrument');22  _istanbulLibInstrument = function () {23    return data;24  };25  return data;26}27function _transform() {28  const data = require('@jest/transform');29  _transform = function () {30    return data;31  };32  return data;33}34function _getRequireWildcardCache(nodeInterop) {35  if (typeof WeakMap !== 'function') return null;36  var cacheBabelInterop = new WeakMap();37  var cacheNodeInterop = new WeakMap();38  return (_getRequireWildcardCache = function (nodeInterop) {39    return nodeInterop ? cacheNodeInterop : cacheBabelInterop;40  })(nodeInterop);41}42function _interopRequireWildcard(obj, nodeInterop) {43  if (!nodeInterop && obj && obj.__esModule) {44    return obj;45  }46  if (obj === null || (typeof obj !== 'object' && typeof obj !== 'function')) {47    return {default: obj};48  }49  var cache = _getRequireWildcardCache(nodeInterop);50  if (cache && cache.has(obj)) {51    return cache.get(obj);52  }53  var newObj = {};54  var hasPropertyDescriptor =55    Object.defineProperty && Object.getOwnPropertyDescriptor;56  for (var key in obj) {57    if (key !== 'default' && Object.prototype.hasOwnProperty.call(obj, key)) {58      var desc = hasPropertyDescriptor59        ? Object.getOwnPropertyDescriptor(obj, key)60        : null;61      if (desc && (desc.get || desc.set)) {62        Object.defineProperty(newObj, key, desc);63      } else {64        newObj[key] = obj[key];65      }66    }67  }68  newObj.default = obj;69  if (cache) {70    cache.set(obj, newObj);71  }72  return newObj;73}74/**75 * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.76 *77 * This source code is licensed under the MIT license found in the78 * LICENSE file in the root directory of this source tree.79 */80async function generateEmptyCoverage(81  source,82  filename,83  globalConfig,84  config,85  changedFiles,86  sourcesRelatedToTestsInChangedFiles87) {88  const coverageOptions = {89    changedFiles,90    collectCoverage: globalConfig.collectCoverage,91    collectCoverageFrom: globalConfig.collectCoverageFrom,92    collectCoverageOnlyFrom: globalConfig.collectCoverageOnlyFrom,93    coverageProvider: globalConfig.coverageProvider,94    sourcesRelatedToTestsInChangedFiles95  };96  let coverageWorkerResult = null;97  if ((0, _transform().shouldInstrument)(filename, coverageOptions, config)) {98    if (coverageOptions.coverageProvider === 'v8') {99      const stat = fs().statSync(filename);100      return {101        kind: 'V8Coverage',102        result: {103          functions: [104            {105              functionName: '(empty-report)',106              isBlockCoverage: true,107              ranges: [108                {109                  count: 0,110                  endOffset: stat.size,111                  startOffset: 0112                }113              ]114            }115          ],116          scriptId: '0',117          url: filename118        }119      };120    }121    const scriptTransformer = await (0, _transform().createScriptTransformer)(122      config123    ); // Transform file with instrumentation to make sure initial coverage data is well mapped to original code.124    const {code} = await scriptTransformer.transformSourceAsync(125      filename,126      source,127      {128        instrument: true,129        supportsDynamicImport: true,130        supportsExportNamespaceFrom: true,131        supportsStaticESM: true,132        supportsTopLevelAwait: true133      }134    ); // TODO: consider passing AST135    const extracted = (0, _istanbulLibInstrument().readInitialCoverage)(code); // Check extracted initial coverage is not null, this can happen when using /* istanbul ignore file */136    if (extracted) {137      coverageWorkerResult = {138        coverage: (0, _istanbulLibCoverage().createFileCoverage)(139          extracted.coverageData140        ),141        kind: 'BabelCoverage'142      };143    }144  }145  return coverageWorkerResult;...

createRuntime.js

Source:createRuntime.js

...79    maxWorkers: 1,80    resetCache: false,81  }).build();82  const cacheFS = new Map();83  const scriptTransformer = await createScriptTransformer(config, cacheFS);84  const runtime = new Runtime(85    config,86    environment,87    Runtime.createResolver(config, hasteMap.moduleMap),88    scriptTransformer,89    cacheFS,90    {91      changedFiles: undefined,92      collectCoverage: false,93      collectCoverageFrom: [],94      collectCoverageOnlyFrom: undefined,95      coverageProvider: 'v8',96      sourcesRelatedToTestsInChangedFiles: undefined,97    },...

runGlobalHook.js

Source:runGlobalHook.js

1'use strict';2Object.defineProperty(exports, '__esModule', {3  value: true4});5exports.default = runGlobalHook;6function util() {7  const data = _interopRequireWildcard(require('util'));8  util = function () {9    return data;10  };11  return data;12}13function _transform() {14  const data = require('@jest/transform');15  _transform = function () {16    return data;17  };18  return data;19}20function _prettyFormat() {21  const data = _interopRequireDefault(require('pretty-format'));22  _prettyFormat = function () {23    return data;24  };25  return data;26}27function _interopRequireDefault(obj) {28  return obj && obj.__esModule ? obj : {default: obj};29}30function _getRequireWildcardCache(nodeInterop) {31  if (typeof WeakMap !== 'function') return null;32  var cacheBabelInterop = new WeakMap();33  var cacheNodeInterop = new WeakMap();34  return (_getRequireWildcardCache = function (nodeInterop) {35    return nodeInterop ? cacheNodeInterop : cacheBabelInterop;36  })(nodeInterop);37}38function _interopRequireWildcard(obj, nodeInterop) {39  if (!nodeInterop && obj && obj.__esModule) {40    return obj;41  }42  if (obj === null || (typeof obj !== 'object' && typeof obj !== 'function')) {43    return {default: obj};44  }45  var cache = _getRequireWildcardCache(nodeInterop);46  if (cache && cache.has(obj)) {47    return cache.get(obj);48  }49  var newObj = {};50  var hasPropertyDescriptor =51    Object.defineProperty && Object.getOwnPropertyDescriptor;52  for (var key in obj) {53    if (key !== 'default' && Object.prototype.hasOwnProperty.call(obj, key)) {54      var desc = hasPropertyDescriptor55        ? Object.getOwnPropertyDescriptor(obj, key)56        : null;57      if (desc && (desc.get || desc.set)) {58        Object.defineProperty(newObj, key, desc);59      } else {60        newObj[key] = obj[key];61      }62    }63  }64  newObj.default = obj;65  if (cache) {66    cache.set(obj, newObj);67  }68  return newObj;69}70/**71 * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.72 *73 * This source code is licensed under the MIT license found in the74 * LICENSE file in the root directory of this source tree.75 */76async function runGlobalHook({allTests, globalConfig, moduleName}) {77  const globalModulePaths = new Set(78    allTests.map(test => test.context.config[moduleName])79  );80  if (globalConfig[moduleName]) {81    globalModulePaths.add(globalConfig[moduleName]);82  }83  if (globalModulePaths.size > 0) {84    for (const modulePath of globalModulePaths) {85      if (!modulePath) {86        continue;87      }88      const correctConfig = allTests.find(89        t => t.context.config[moduleName] === modulePath90      );91      const projectConfig = correctConfig92        ? correctConfig.context.config // Fallback to first config93        : allTests[0].context.config;94      const transformer = await (0, _transform().createScriptTransformer)(95        projectConfig96      );97      try {98        await transformer.requireAndTranspileModule(99          modulePath,100          async globalModule => {101            if (typeof globalModule !== 'function') {102              throw new TypeError(103                `${moduleName} file must export a function at ${modulePath}`104              );105            }106            await globalModule(globalConfig);107          }108        );109      } catch (error) {110        if (util().types.isNativeError(error)) {111          error.message = `Jest: Got error running ${moduleName} - ${modulePath}, reason: ${error.message}`;112          throw error;113        }114        throw new Error(115          `Jest: Got error running ${moduleName} - ${modulePath}, reason: ${(0,116          _prettyFormat().default)(error, {117            maxDepth: 3118          })}`119        );120      }121    }122  }...

index.js

Source:index.js

1'use strict';2Object.defineProperty(exports, '__esModule', {3  value: true4});5Object.defineProperty(exports, 'createScriptTransformer', {6  enumerable: true,7  get: function () {8    return _ScriptTransformer.createScriptTransformer;9  }10});11Object.defineProperty(exports, 'createTranspilingRequire', {12  enumerable: true,13  get: function () {14    return _ScriptTransformer.createTranspilingRequire;15  }16});17Object.defineProperty(exports, 'handlePotentialSyntaxError', {18  enumerable: true,19  get: function () {20    return _enhanceUnexpectedTokenMessage.default;21  }22});23Object.defineProperty(exports, 'shouldInstrument', {24  enumerable: true,25  get: function () {26    return _shouldInstrument.default;27  }28});29var _ScriptTransformer = require('./ScriptTransformer');30var _shouldInstrument = _interopRequireDefault(require('./shouldInstrument'));31var _enhanceUnexpectedTokenMessage = _interopRequireDefault(32  require('./enhanceUnexpectedTokenMessage')33);34function _interopRequireDefault(obj) {35  return obj && obj.__esModule ? obj : {default: obj};...

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What is Jest Framework
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|it('check_object_of_Car', () => { expect(newCar()).toBeInstanceOf(Car); });| | :- |

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