index.js

/* eslint-disable no-process-env */
var CachedSource = require('webpack-core/lib/CachedSource');
var ConcatSource = require('webpack-core/lib/ConcatSource');

var path = require('path');
var url = require('url');
var uglifyJs = require('uglify-js');
var build = require('modernizr').build;
var assign = require('object-assign');

process.env.NODE_ENV = (process.env.NODE_ENV || 'development').trim();

/**
 *
 * @constructor
 */
function ModernizrPlugin(options) {
  options = options || {};
  // ensure extension on filename
  if (options.filename && !options.filename.match(/\.js$/)) {
    options.filename = options.filename + '.js';
  }

  // regression support for namechange 1.0.0+
  if (options.htmlWebPackPluginIntegration !== undefined) {
    options.htmlWebpackPlugin = options.htmlWebPackPluginIntegration;
  }

  this.options = assign({}, {
    filename: 'modernizr-bundle.js',
    htmlWebpackPlugin: true,
    minify: process.env.NODE_ENV === 'production',
    noChunk: false
  }, options);
}

ModernizrPlugin.prototype.htmlWebpackPluginInject = function (plugin, filename, filePath, filesize, noChunk) {
  var htmlWebPackPluginAssets = plugin.htmlWebpackPluginAssets;
  plugin.htmlWebpackPluginAssets = function () {
    var result = htmlWebPackPluginAssets.apply(plugin, arguments);
    if (noChunk) {
      result[filename] = filePath;
    } else {
      var chunk = {};
      chunk[filename] = {
        entry: filePath,
        css: [],
        size: filesize || 0
      };
      // get html-webpack-plugin to output modernizr chunk first
      result.chunks = assign({}, chunk, result.chunks);
    }
    return result;
  };
};

ModernizrPlugin.prototype.minifySource = function (source, options) {
  var uglifyOptions = assign({}, options, {fromString: true});
  return uglifyJs.minify(source, uglifyOptions).code;
};

/**
 * Copied from html-webpack-plugin
 * @param {Object} compilation
 * @param {string} filename
 * @returns {string} Webpack public path option
 * @private
 */
ModernizrPlugin.prototype.resolvePublicPath = function (compilation, filename) {
  var publicPath = typeof compilation.options.output.publicPath !== 'undefined' ?
    compilation.mainTemplate.getPublicPath({hash: compilation.hash}) :
    path.relative(path.dirname(filename), '.');

  if (publicPath.length && publicPath.substr(-1, 1) !== '/') {
    publicPath = path.join(url.resolve(publicPath + '/', '.'), '/');
  }

  return publicPath
};

ModernizrPlugin.prototype.createHash = function (output, length) {
  var hash = require('crypto').createHash('md5');
  hash.update(output);
  return hash.digest('hex').substr(0, length);
};

ModernizrPlugin.prototype.createOutputPath = function (oFilename, publicPath, hash) {
  var result = oFilename;
  if (publicPath) {
    result = publicPath + oFilename;
  }
  if (hash) {
    result = result + (result.indexOf('?') === -1 ? '?' : '&') + hash;
  }
  return result;
};

ModernizrPlugin.prototype.validatePlugin = function (plugin) {
  return !(typeof plugin !== 'object' || typeof plugin.htmlWebpackPluginAssets !== 'function');
};

ModernizrPlugin.prototype.apply = function (compiler) {
  var self = this;

  (compiler.hooks ? compiler.hooks.afterCompile.tapAsync.bind(compiler.hooks.afterCompile, 'ModernizrWebpackPlugin') : compiler.plugin.bind(compiler, 'after-compile'))((compilation, cb) => {

    var buildOptions = assign({}, self.options);

    build(buildOptions, function (output) {
      if (buildOptions.minify) {
        output = self.minifySource(output, buildOptions.minify);
      }
      self.modernizrOutput = output;
      var publicPath = self.resolvePublicPath(compilation, buildOptions.filename);
      var filename = buildOptions.filename;
      if (/\[hash\]/.test(buildOptions.filename)) {
        self.oFilename = filename.replace(/\[hash\]/, compilation.hash);
        filename = filename.replace(/\[hash\]/, '');
      } else if (/\[chunkhash\]/.test(buildOptions.filename)) {
        self.oFilename = filename.replace(/\[chunkhash\]/, self.createHash(output,
          compiler.options.output.hashDigestLength));
        filename = filename.replace(/\[chunkhash\]/, '');
      } else {
        self.oFilename = filename;
      }
      var plugins = [], plugin = buildOptions.htmlWebpackPlugin;
      var filterFunct = function (plugin, error) {
        if (self.validatePlugin(plugin)) {
          return true;
        }
        if (typeof error === 'boolean' && error) {
          compilation.errors.push(new Error('Unable to inject into html-webpack-plugin instance.\n' +
            'Please log issue at https://github.com/alexpalombaro/modernizr-webpack-plugin/issues.'));
        }
      };
      switch (typeof plugin) {
        case 'array':
          plugins = plugin.filter(function (plugin) {
            return filterFunct(plugin, true);
          });
          break;
        case 'object':
          if (filterFunct(plugin, true)) {
            plugins.push(plugin);
          }
          break;
        case 'boolean':
          plugins = plugin ? compiler.options.plugins.filter(filterFunct) : [];
          break;
      }
      plugins.forEach(function (plugin) {
        var filePath = self.createOutputPath(self.oFilename, publicPath,
          plugin.options.hash ? compilation.hash : null);
        self.htmlWebpackPluginInject(plugin, path.basename(filename, '.js'), filePath,
          output.length, buildOptions.noChunk)
      });
      cb();
    })
  });

  (compiler.hooks ? compiler.hooks.emit.tapAsync.bind(compiler.hooks.emit, 'ModernizrWebpackPlugin') : compiler.plugin.bind(compiler, 'emit'))((compilation, cb) => {
    var source = new ConcatSource();

    source.add(self.modernizrOutput);

    var filename = self.oFilename;
    compilation.assets[filename] = new CachedSource(source);

    cb();
  });
};

module.exports = ModernizrPlugin;