| 1 | # babel-jest
|
| 2 |
|
| 3 | [Babel](https://github.com/babel/babel) [jest](https://github.com/facebook/jest)
|
| 4 | plugin
|
| 5 |
|
| 6 | ## Usage
|
| 7 |
|
| 8 | If you are already using `jest-cli`, just add `babel-jest` and it will
|
| 9 | automatically compile JavaScript code using babel.
|
| 10 |
|
| 11 | ```bash
|
| 12 | yarn add --dev babel-jest babel-core
|
| 13 | ```
|
| 14 |
|
| 15 | > Note: If you are using babel version 7 you have to install `babel-jest` with
|
| 16 | >
|
| 17 | > ```bash
|
| 18 | > yarn add --dev babel-jest babel-core@^7.0.0-0 @babel/core
|
| 19 | > ```
|
| 20 |
|
| 21 | If you would like to write your own preprocessor, uninstall and delete
|
| 22 | babel-jest and set the
|
| 23 | [config.transform](http://facebook.github.io/jest/docs/configuration.html#transform-object-string-string)
|
| 24 | option to your preprocessor.
|
| 25 |
|
| 26 | ## Setup
|
| 27 |
|
| 28 | _Note: this step is only required if you are using `babel-jest` with additional
|
| 29 | code preprocessors._
|
| 30 |
|
| 31 | To explicitly define `babel-jest` as a transformer for your JavaScript code, map
|
| 32 | _.js_ files to the `babel-jest` module.
|
| 33 |
|
| 34 | ```json
|
| 35 | "transform": {
|
| 36 | "^.+\\.jsx?$": "babel-jest"
|
| 37 | },
|
| 38 | ```
|