merge-json-webpack-plugin/README.md

Webpack plugin to merge multiple json files into one

# merge-json-webpack-plugin

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> Webpack plugin to merge multiple json files into one

<p align="center">
  <a href="https://github.com/sibiraj-s/merge-json-webpack-plugin">
    <img width="200" height="200" src="./assets/webpack.png">
  </a>
</p>

## Getting Started

### Installation

```bash
npm i -D merge-json-webpack-plugin
# or
yarn add --dev merge-json-webpack-plugin
```

### Usage

```js
// webpack.config.js
const MergeJsonPlugin = require('merge-json-webpack-plugin');

module.exports = {
  plugins: [
    new MergeJsonPlugin({
      force: false,
      groups: [
        {
          files: [
            'common-manifest.json',
            'firefox-manifest.json'
          ],
          transform: (outputJson) => outputJson,
          to: 'manifest.json',
        },
        {
          pattern: '*.json', // glob. see https://github.com/mrmlnc/fast-glob
          to: 'merged-[contenthash].json',
        },
      ],
    }),
  ],
};
```

### Options

- **cwd**[`string`] - The directory, an absolute path, for resolving files. Defaults to webpack [context](https://webpack.js.org/configuration/entry-context/#context)

- **groups**[`array`] - Files to merge and destination path

  - **files**[`string[]`] - Array of files, path resolved relative to `cwd`.
  - **pattern**[`string[]`] or [`string`] - [[Fast-Glob](https://github.com/mrmlnc/fast-glob)] pattern matching. The order of merge is not guarenteed.
  - **transform**[`function`] - A function to modify the merged json contents. The return json value is written to the output file. If the function returns a promise, it will be awaited.
  - **to**[`string`]: Destination path to write the files to.
  - **globOptions**[`GlobOptions`] - Options to foward to `fast-glob` when glob is used otherwise ignored. See https://github.com/mrmlnc/fast-glob#options-3.

- **minify**[`boolean`] - Minify the output json. Enabled by default in production mode.

- **mergeFn**[`function`] - A function used to merge two objects. Defaults to `Object.assign`.

```js
// webpack.config.js
const MergeJsonPlugin = require('merge-json-webpack-plugin');
const _ = require('loadsh');

const customizer = (objValue, srcValue) => {
  if (_.isArray(objValue)) {
    return objValue.concat(srcValue);
  }
};

const merge = (object, other) => {
  return _.mergeWith(object, other, customizer);
};

module.exports = {
  plugins: [
    new MergeJsonPlugin({
      mergeFn: merge,
    }),
    new MergeJsonPlugin({
      mergeFn: (prev, current) => Object.assign(prev, current),
    }),
  ],
};
```

- **force**[`boolean`] - Overwrites files already in compilation.assets (usually added by other plugins/loaders). Disabled by default.

- **globOptions**[`GlobOptions`] - Options to foward to `fast-glob` when glob is used otherwise ignored. See https://github.com/mrmlnc/fast-glob#options-3.