install-nix-action/node_modules/babel-jest/README.md

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2019-11-20 03:50:30 +11:00
# babel-jest
[Babel](https://github.com/babel/babel) [jest](https://github.com/facebook/jest) plugin
## Usage
If you are already using `jest-cli`, just 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": {
"^.+\\.[t|j]sx?$": "babel-jest"
},
```