README.md•823 B
# babel-jest
[Babel](https://github.com/babel/babel) [jest](https://github.com/jestjs/jest) plugin
## Usage
If you are already using `jest-cli`, add `babel-jest` and it will automatically compile JavaScript code using Babel.
```bash
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](https://jestjs.io/docs/configuration#transform-object-string-string) 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.
```json
"transform": {
"\\.[jt]sx?$": "babel-jest"
},
```