# @unic/estatico-webpack

Uses Webpack with Babel to transpile and bundle JavaScript.

## Installation

```
$ npm install --save-dev @unic/estatico-webpack
```

## Usage

It is recommended to use the tools' default config files. Specifically, creating a `webpack.config.js`, `.babelrc.js` and `.browserslistrc`, possibly extending the default ones. This will make the configs more portable and make them usable outside of this task.

The webpack config needs to be passed to the task, babel and browserslist are picked up automagically if present. (This would allow you to skip the default config files and just pass your webpack config to the task directly, if you prefer this approach.)

```js
const gulp = require('gulp');

/**
 * JavaScript bundling task
 * Uses Webpack with Babel to transpile and bundle JavaScript.
 *
 * Using `--watch` (or manually setting `env` to `{ watch: true }`) starts file watcher
 */
gulp.task('js', (cb) => {
  const task = require('@unic/estatico-webpack');
  const webpackConfig = require('./webpack.config.js');

  const instance = task(defaults => ({
    webpack: webpackConfig,
    logger: defaults.logger,
  }), env);

  return instance(cb);
});
```

`webpack.config.js` extending the default one:

```js
const defaults = require('@unic/estatico-webpack/webpack.config.js');
const env = require('minimist')(process.argv.slice(2));
const merge = require('lodash.merge');
const path = require('path');

module.exports = merge({}, defaults, {
  entry: Object.assign({
    head: './src/assets/js/head.js',
    main: './src/assets/js/main.js',
  }, (env.dev || env.ci) ? {
    dev: './src/assets/js/dev.js',
  } : {}),
  output: {
    path: path.resolve('./dist/assets/js'),
    filename: `[name]${env.dev ? '' : '.min'}.js`,
    chunkFilename: `async/[name]${env.dev ? '' : '.min'}.js`,
    publicPath: '/assets/js/',
  },
  mode: env.dev ? 'development' : 'production',
});
```

`.babelrc.js` extending the default one:

```js
module.exports = {
  extends: '@unic/estatico-webpack/.babelrc.js',
};
```

`.browserslistrc`:

```js
> 1%
```

Run task (assuming the project's `package.json` specifies `"scripts": { "gulp": "gulp" }`):
`$ npm run gulp js`

See possible flags specified above.

## API

`plugin(options, env)` => `taskFn`

### Options

#### webpack

Type: `Object`<br>
Default:
```js
{
  resolve: {
    alias: {
      handlebars: 'handlebars/runtime.js',
    },
  },
  module: {
    rules: [
      {
        test: /jquery\.js$/,
        loader: 'expose-loader?$!expose-loader?jQuery',
      },
      {
        test: /modernizrrc\.js$/,
        loader: 'expose-loader?Modernizr!webpack-modernizr-loader',
      },
      {
        test: /\.hbs$/,
        loader: 'handlebars-loader',
      },
      {
        test: /(\.js|\.jsx)$/,
        exclude: /node_modules/,
        loader: 'babel-loader',
        options: {
          // See .babelrc.js
        },
      },
    ],
  },

  // Custom UglifyJS options
  optimization: {
    minimizer: [
      new UglifyJSPlugin({
        uglifyOptions: {
          mangle: {
            keep_fnames: true,
          },
        },
      }),
    ],
  },
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerMode: 'static',
      // Path to bundle report file that will be generated in `static` mode.
      // Relative to bundles output directory.
      reportFilename: 'report.html',
      openAnalyzer: false,
      logLevel: 'warn',
    }),
    new UnminifiedWebpackPlugin(),
  ],
}
```

#### logger

Type: `{ info: Function, debug: Function, error: Function }`<br>
Default: Instance of [`estatico-utils`](../estatico-utils)'s `Logger` utility.

Set of logger utility functions used within the task.

## License

Apache 2.0.