https://github.com/papermana/jest-alias-preprocessor

A preprocessor for Jest with support for webpack aliases
https://github.com/papermana/jest-alias-preprocessor

Last synced: 2 months ago
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A preprocessor for Jest with support for webpack aliases

• Host: GitHub
• URL: https://github.com/papermana/jest-alias-preprocessor
• Owner: papermana
• License: mit
• Created: 2016-07-15T21:09:12.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2017-06-16T11:18:27.000Z (over 7 years ago)
• Last Synced: 2024-10-08T20:07:21.634Z (3 months ago)
• Language: JavaScript
• Size: 22.5 KB
• Stars: 2
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md
  • License: LICENSE.md

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README

        
# jest-alias-preprocessor

This package allows you to use aliases when testing with [Jest](https://github.com/facebook/jest). It's very handy when you want to use your existing [webpack](https://github.com/webpack/webpack) configuration, but you can also use it on its own.

Really, it's just a very simple wrapper on top of [transform-jest-deps](https://github.com/Ticketmaster/transform-jest-deps).

## Usage

`jest-alias-preprocessor` exports a higher-order function; to make it work, you have to provide a configuration object for it to use. Simply create a new file, import this module, and either import `webpack.config.js`, or create a new object from scratch. Then, invoke the function, passing the config as an argument. Finally, link to the preprocessor from your Jest configuration using the `scriptPreprocessor` option.

Note that your config has to look like a webpack config object even if you don't use webpack. It needs a `resolve` property, and that property needs to have a `root` and `alias` property. You can see how it looks below.

### Example 1 ― everything in root directory

```

const config = require('./webpack.config.js');

module.exports = require('jest-alias-preprocessor')(config);

```

### Example 2 ― no Webpack config

```

module.exports = require('jest-alias-preprocessor')({

  resolve: {

    root: process.cwd(),

    alias: {

      _js: './app/js',

      _utils: './app/js/utils',

    },

  },

});

```

### Example 3 ― with babel-jest

```

var config = require('./webpack.config.js');

var aliasPreprocessor = require('jest-alias-preprocessor')(config);

var babel = require('babel-jest');

module.exports = {

  process: function(src, path) {

    src = aliasPreprocessor.process(src, path);

    src = babel.process(src, path);

    return src;

  },

};

```