babel-jest

babel-jest

Babel jest plugin

Usage

If you are already using jest-cli, add babel-jest and it will automatically compile JavaScript code using Babel.

yarn add --dev babel-jest @babel/core

If you would like to write your own preprocessor, uninstall and delete babel-jest and set the config.transform option to your preprocessor.

Setup

Note: this step is only required if you are using babel-jest with additional code preprocessors.

To explicitly define babel-jest as a transformer for your JavaScript code, map .js files to the babel-jest module. Typescript files are also supported.

By default, it loads your existing Babel configuration (if any)

"transform": {
  "\\.[jt]sx?$": "babel-jest"
},

You can also pass further babel options

"transform": {
  "\\.[jt]sx?$": ["babel-jest", { "extends": "./babel.config.js", "plugins": ["babel-plugin-transform-import-meta"] }]
},

By default, babel-jest includes babel-preset-jest. In addition to the babel options, we introduce a new option, excludeJestPreset, which allows you to disable this behavior. Note that this will break jest.mock hoisting.

"transform": {
  "\\.[jt]sx?$": ["babel-jest", { "excludeJestPreset": true }],
}

Similar packages

Other packages similar to babel-jest

ts-jest

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

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

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.