babel-jest
Advanced tools
[Babel](https://github.com/babel/babel) [jest](https://github.com/facebook/jest) plugin
The babel-jest package is a Jest plugin that makes it easy to use Babel to transform your JavaScript tests. It automatically hooks Babel into Jest and compiles files before running them, allowing you to use the latest JavaScript features and syntax in your test files.
Transforming test files with Babel
This configuration in Jest's setup file tells Jest to use babel-jest for transforming any files that match the regex pattern (in this case, any JavaScript files) before running the tests.
module.exports = {
transform: {
'^.+\\.js$': 'babel-jest'
}
};Using modern JavaScript syntax in tests
With babel-jest, you can write tests using modern JavaScript features like async/await without worrying about compatibility issues.
test('async/await works', async () => {
const data = await fetchData();
expect(data).toBe('expected data');
});Custom Babel configuration
babel-jest allows you to specify a custom Babel configuration to tailor the transformation process to your project's needs.
{
'presets': [['@babel/preset-env', { 'targets': { 'node': 'current' } }]],
'plugins': ['@babel/plugin-proposal-class-properties']
}ts-jest is a TypeScript preprocessor with source map support for Jest. It allows you to use Jest to test projects written in TypeScript. It is similar to babel-jest but specifically tailored for TypeScript rather than general Babel transformations.
jest-transform-stub is a package that allows you to stub out resources, like images or styles, during testing with Jest. It is similar to babel-jest in that it transforms assets, but it focuses on non-JavaScript assets instead of JavaScript code.
jest-vue-preprocessor is a preprocessor for Jest to handle .vue files, allowing you to test Vue components. It is similar to babel-jest in the sense that it preprocesses files for testing, but it is specifically designed for Vue components.
Make the following changes to package.json:
{
"dependencies": {
"babel-jest": "*",
"jest": "*"
},
"scripts": {
"test": "jest"
},
"jest": {
"scriptPreprocessor": "<rootDir>/node_modules/babel-jest",
"testFileExtensions": ["es6", "js"],
"moduleFileExtensions": ["js", "json", "es6"]
}
}
And run:
$ npm install
And you're good to go!
24.0.0
[jest-each] [BREAKING] Add primitive pretty printing for interpolated titles (#7694)[jest-runtime] Add jest.isolateModules for scoped module initialization (#6701)[jest-diff] [BREAKING] Support diffing numbers and booleans instead of returning null for different ones (#7605)[jest-diff] [BREAKING] Replace diff with diff-sequences package (#6961)[jest-cli] [BREAKING] Only set error process error codes when they are non-zero (#7363)[jest-config] [BREAKING] Deprecate setupTestFrameworkScriptFile in favor of new setupFilesAfterEnv (#7119)[jest-worker] [BREAKING] Add functionality to call a setup method in the worker before the first call and a teardown method when ending the farm (#7014)[jest-config] [BREAKING] Set default notifyMode to failure-change (#7024)[jest-haste-map] [BREAKING] Remove support for @providesModule (#6104)[jest-haste-map] [BREAKING] Replace internal data structures to improve performance (#6960)[jest-haste-map] [BREAKING] Use relative paths to allow remote caching (#7020)[jest-haste-map] [BREAKING] Remove name from hash in HasteMap.getCacheFilePath (#7218)[babel-preset-jest] [BREAKING] Export a function instead of an object for Babel 7 compatibility (#7203)[jest-haste-map] [BREAKING] Expose relative paths when getting the file iterator (#7321)[jest-cli] [BREAKING] Run code transforms over global{Setup,Teardown} (#7562)[jest-haste-map] Add hasteFS.getSize(path) (#7580)[jest-cli] Print version ending in -dev when running a local Jest clone (#7582)[jest-cli] Add Support for globalSetup and globalTeardown in projects (#6865)[jest-runtime] Add extraGlobals to config to load extra global variables into the execution vm (#7454)[jest-util] Export specialChars containing Unicode characters and ANSI escapes for console output (#7532)[jest-config] Handle typescript (ts and tsx) by default (#7533)[jest-validate] Add support for comments in package.json using a "//" key (#7295)[jest-config] Add shorthand for watch plugins and runners (#7213)[jest-jasmine2/jest-circus/jest-cli] Add test.todo (#6996)[pretty-format] Option to not escape strings in diff messages (#5661)[jest-haste-map] Add getFileIterator to HasteFS for faster file iteration (#7010)[jest-config] Add readConfigs function, previously in jest-cli (#7096)[jest-snapshot] Enable configurable snapshot paths (#6143)[pretty-format] Support HTMLCollection and NodeList in DOMCollection plugin (#7125)[jest-runtime] Pass the normalized configuration to script transformers (#7148)[expect] Improve report when assertion fails, part 3 (#7152)[jest-runtime] If require fails without a file extension, print all files that match with one (#7160)[jest-haste-map] Make ignorePattern optional (#7166)[jest-haste-map] Add getCacheFilePath to get the path to the cache file for a HasteMap instance (#7217)[jest-runtime] Remove cacheDirectory from ignorePattern for HasteMap if not necessary (#7166)[jest-validate] Add syntax to validate multiple permitted types (#7207)[jest-config] Accept an array as as well as a string for testRegex (#7209)[expect/jest-matcher-utils] Improve report when assertion fails, part 4 (#7241)[expect/jest-matcher-utils] Improve report when assertion fails, part 5 (#7557)[expect] Check constructor equality in .toStrictEqual() (#7005)[jest-util] Add jest.getTimerCount() to get the count of scheduled fake timers (#7285)[jest-config] Add dependencyExtractor option to use a custom module to extract dependencies from files (#7313, #7349, #7350, #7362)[jest-haste-map] Accept a getCacheKey method in hasteImplModulePath modules to reset the cache when the logic changes (#7350)[jest-config] Add haste.computeSha1 option to compute the sha-1 of the files in the haste map (#7345)[expect] expect(Infinity).toBeCloseTo(Infinity) Treats Infinity as equal in toBeCloseTo matcher (#7405)[jest-worker] Add node worker-thread support to jest-worker (#7408)[jest-config] Allow bail setting to be configured with a number allowing tests to abort after n of failures (#7335)[jest-config] Allow % based configuration of --max-workers (#7494)[jest-runner] Instantiate the test environment class with the current testPath (#7442)[jest-config] Always resolve jest-environment-jsdom from jest-config (#7476)[expect] Improve report when assertion fails, part 6 (#7621)[jest-worker] Add enableWorkerThreads option to explicitly opt-in to worker_threads if available (#7681)[expect] Accept inherited properties in toHaveProperty matcher (#7686)[jest-diff] Do not claim that -0 and 0 have no visual difference (#7605)[jest-mock] Fix automock for numeric function names (#7653)[jest-config] Ensure existsSync is only called with a string parameter (#7607)[expect] toStrictEqual considers sparseness of arrays. (#7591)[jest-cli] Fix empty coverage data for untested files (#7388)[jest-cli] [BREAKING] Do not use text-summary coverage reporter by default if other reporters are configured (#7058)[jest-mock] [BREAKING] Fix bugs with mock/spy result tracking of recursive functions (#6381)[jest-haste-map] [BREAKING] Recover files correctly after haste name collisions are fixed (#7329)[pretty-format] [BREAKING] Omit non-enumerable symbol properties (#7448)[*] [BREAKING] Upgrade to Babel 7, dropping support for Babel 6 (#7016)[jest-cli] Avoid watch mode causing bad terminal behavior in some cases (#7523)[jest-runner/jest-worker] Fix missing console output in verbose mode (#6871)[expect] Standardize file naming in expect (#7306)[jest-each] Add empty array validation check (#7249)[jest-cli] Interrupt tests if interactive watch plugin key is pressed (#7222)[jest-each] Add each array validation check (#7033)[jest-haste-map] Do not visit again files with the same sha-1 (#6990)[jest-jasmine2] Fix memory leak in Error objects hold by the framework (#6965)[jest-haste-map] Fixed Haste whitelist generation for scoped modules on Windows (#6980)[jest-mock] Fix inheritance of static properties and methods in mocks (#7003)[jest-mock] Fix mocking objects without Object.prototype in their prototype chain (#7003)[jest-mock] Check _isMockFunction is true rather than truthy on potential mocks (#7017)[jest-cli] Update jest-cli to show git ref in message when using changedSince (#7028)[jest-jasmine2] Fix crash when test return Promise rejected with null (#7049)[jest-runtime] Check _isMockFunction is true rather than truthy on potential global mocks (#7017)[jest-jasmine] Show proper error message from async assert errors (#6821)[jest-jasmine2] Better error message when a describe block is empty (#6372)[jest-jasmine2] Pending calls inside async tests are reported as pending not failed (#6782)[jest-circus] Better error message when a describe block is empty (#6372)[jest-jasmine2] Add missing testLocationResults for xit and fit (#6482)[expect] Return false from asymmetric matchers if received value isn’t string (#7107)[jest-cli] Fix unhandled error when a bad revision is provided to changedSince (#7115)[jest-config] Moved dynamically assigned cwd from jest-cli to default configuration in jest-config (#7146)[jest-config] Fix getMaxWorkers on termux (#7154)[jest-runtime] Throw an explicit error if js is missing from moduleFileExtensions (#7160)[jest-runtime] Fix missing coverage when using negative glob pattern in testMatch (#7170)[*] Ensure maxWorkers is at least 1 (was 0 in some cases where there was only 1 CPU) (#7182)[jest-runtime] Fix transform cache invalidation when requiring a test file from multiple projects (#7186)[jest-changed-files] Return correctly the changed files when using lastCommit=true on Mercurial repositories (#7228)[babel-jest] Cache includes babel environment variables (#7239)[jest-config] Use strings instead of RegExp instances in normalized configuration (#7251)[jest-circus] Make sure to display real duration even if time is mocked (#7264)[expect] Improves the failing message for toStrictEqual matcher. (#7224)[expect] Improves the failing message for toEqual matcher. (#7325)[jest-resolve] Fix not being able to resolve path to mapped file with custom platform (#7312)[jest-message-util] Improve parsing of error messages for unusually formatted stack traces (#7319)[jest-runtime] Ensure error message text is not lost on errors with code frames (#7319)[jest-haste-map] Fix to resolve path that is start with words same as rootDir (#7324)[expect] Fix toMatchObject matcher when used with Object.create(null) (#7334)[jest-haste-map] Remove legacy condition for duplicate module detection (#7333)[jest-haste-map] Fix require detection with trailing commas and ignore import typeof modules (#7385)[jest-cli] Fix to set prettierPath via config file (#7412)[expect] Test more precisely for class instance getters (#7477)[jest-cli] Support dashed args (#7497)[jest-cli] Fix to run in band tests if watch mode enable when runInBand arg used (#7518)[jest-runtime] Fix mistake as test files when run coverage issue. (#7506)[jest-cli] print info about passWithNoTests flag (#7309)[pretty-format] Omit unnecessary symbol filter for object keys (#7457)[jest-runtime] Fix requireActual on node_modules with mock present (#7404)[jest-resolve] Fix isBuiltinModule to support versions of node without module.builtinModules (#7565)[babel-jest] Set cwd to be resilient to it changing during the runtime of the tests (#7574)[jest-snapshot] Write and read snapshots from disk even if fs is mocked (#7080)[jest-config] Normalize config.cwd and config.rootDir using `realpath (#7598)[jest-environment-node] Fix buffer property is not ArrayBuffer issue. (#7626)[babel-plugin-jest-hoist] Ignore TS type annotations when looking for out-of-scope references (#7641)[jest-config] Add name to project if one does not exist to pick correct resolver (#5862)[jest-runtime] Pass watchPathIgnorePatterns to Haste instance (#7585)[jest-runtime] Resolve mock files via Haste when using require.resolve (#7687)[*] [BREAKING] Require Node.js 6+ for all packages (#7258)[jest-util] [BREAKING] Remove long-deprecated globals for fake timers (#7285)[*] [BREAKING] Upgrade to Micromatch 3 (#6650)[*] [BREAKING] Remove regenerator-runtime injection (#7595)[jest-worker] Disable worker_threads to avoid issues with libraries to ready for it (#7681)[docs] Fix message property in custom matcher example to return a function instead of a constant. (#7426)[jest-circus] Standardize file naming in jest-circus (#7301)[docs] Add synchronous test.each setup (#7150)[docs] Add this.extend to the Custom Matchers API reference (#7130)[docs] Fix default value for coverageReporters value in configuration docs (#7126)[docs] Add link for jest-extended in expect docs (#7078)[jest-util] Add ErrorWithStack class (#7067)[docs] Document --runTestsByPath CLI parameter (#7046)[docs] Fix babel-core installation instructions (#6745)[docs] Explain how to rewrite assertions to avoid large irrelevant diff (#6971)[examples] add example using Babel 7 (#6983)[docs] Replace shallow equality with referential identity in ExpectAPI.md (#6991)[jest-changed-files] Refactor to use execa over child_process (#6987)[*] Bump dated dependencies (#6978)[scripts] Don’t make empty sub-folders for ignored files in build folder (#7001)[docs] Add missing export statement in puppeteer_environment.js under docs/Puppeteer.md (#7127)[docs] Removed useless expect.assertions in TestingAsyncCode.md (#7131)[docs] Remove references to @providesModule which isn't supported anymore (#7147)[docs] Update setupFiles documentation for clarity (#7187)[docs] Change require.require* to jest.require* (#7210)[jest-circus] Add readme.md (#7198)[jest-editor-support] Remove from the repository (#7232)[jest-test-typescript-parser] Remove from the repository (#7232)[tests] Free tests from the dependency on value of FORCE_COLOR (#6585)[*] Add babel plugin to make sure Jest is unaffected by fake Promise implementations (#7225)[docs] Add correct default value for testUrl config option (#7277)[docs] Remove duplicate code in MockFunctions (#7297)[*] Add check for Facebook copyright headers on CI (#7370)[*] Update Facebook copyright headers (#7589)[jest-haste-map] Refactor dependencyExtractor and tests (#7385)[docs] Clearify conditional setting of NODE_ENV (#7369)[docs] Clarify conditional setting of NODE_ENV (#7369)[*] Standardize file names (#7316, #7266, #7238, #7314, #7467, #7464), #7471)[docs] Add testPathIgnorePatterns in CLI documentation (#7440)[docs] Removed misleading text about describe() grouping together tests into a test suite (#7434)[diff-sequences] Add performance benchmark to package (#7603)[*] Replace as many Object.assign with object spread as possible (#7627)[ci] Initial support for Azure Pipelines (#7556)[jest-mock] Improve getType function performance. (#7159)FAQs
Jest plugin to use babel for transformation.
The npm package babel-jest receives a total of 23,201,656 weekly downloads. As such, babel-jest popularity was classified as popular.
We found that babel-jest demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 3 open source maintainers collaborating on the project.
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