sri-stats-webpack-plugin

Most of the code based on @roman01la's webpack-sri.

This is a webpack plugin which generates a subresource integrity hash. It adds the hash to webpack's stats object.

It creates a direct mapping with [asset] => sri hash, and another mapping of [asset] => { [integrityKey]: hash }.

The direct mapping is saved into webpack's compilation, while the secondary mapping is saved into stats.toJson().

Example:

// webpack stats

compilation.getStats().toJson().sris
# => {
  'main-459130c16ce3c68b595e.js': {
    integrity: 'sha384-Lgg9yFvipJWo8BEZOJhBN2wCPtr/RVl9EWeXFHUzQKtUduAyATSIl79NJbfzZT8p'
  }
}

// webpack compilation

compilation.__RESULTS_SRIS
# => {
  'main-459130c16ce3c68b595e.js': 'sha384-Lgg9yFvipJWo8BEZOJhBN2wCPtr/RVl9EWeXFHUzQKtUduAyATSIl79NJbfzZT8p'
}

Setup

npm install sri-stats-webpack-plugin --save-dev

Usage

// Your webpack config

var path = require('path');
var SriStatsPlugin = require('sri-stats-webpack-plugin');

var config = {
  plugins: [
    new SriStatsPlugin({
      algorithm: 'sha512',
      allow: (/\.(js|css)$/i/),
      customStatsKey: 'rails',
      assetKey: 'integrity',
      saveAs: path.join(__dirname, 'build', 'subresource-integrity-mapping.json'),
      write: true,
      writeDirectMapping: true,
      resultsKey: '__RESULTS_SRIS',
      runAfterEmit: true
    })
 ]
};

Configuration

• algorithm: The hashing algorithm to use. Default: sha384
• allow: This is a regex to allow what files should be hashed. The default regex is set to allow only .js or .css files. Default: /\.(js|css)$/i/
• customStatsKey: This is the parent key the mapping is saved to. You will probably want to change this if you are using it with the SprocketsStatsWebpackPlugin. Default: sris
• assetKey: This is the child key that the hash will be associated to. Default: integrity
• saveAs: Absolute path to where to save the output to. Default: path.join(process.env.WEBPACK_OUTPUT_PATH, 'build', 'subresource-integrity-mapping.json'). If WEBPACK_OUTPUT_PATH, is not specified, it will fallback to process.cwd().
• write: Boolean option, of whether to write the stats file or not. Default: false
• writeDirectMapping: Boolean option, enables writing [asset] => [hash]. Otherwise it will write it as [asset] => { [integrityKey] => [hash] }. Default: true
• resultsKey: Where to save the results to in webpack's compilation object. Default: __RESULTS_SRIS
• runAfterEmit: Boolean option, whether to calculate hashes during or after emit stage. If HTMLWebpackPlugin is supposed to pick up the hashes (during emit stage), set to false and run this plugin first. Default: true

License

MIT.