Use last-call-webpack-plugin

Bring back cssnano to dependencies (from peerDependencies).

Author: NMFR

README.md

@@ -6,8 +6,6 @@ A Webpack plugin to optimize \ minimize CSS assets.
 
 It will search for CSS assets during the Webpack build and will optimize \ minimize the CSS (by default it uses [cssnano](http://github.com/ben-eb/cssnano) but a custom CSS processor can be specified).
 
-Note: To use the default CSS processor, [cssnano](http://github.com/ben-eb/cssnano) must be explicitly installed (since it's a peer dependency).
-
 ### Solves [extract-text-webpack-plugin](http://github.com/webpack/extract-text-webpack-plugin) CSS duplication problem:
 
 Since [extract-text-webpack-plugin](http://github.com/webpack/extract-text-webpack-plugin) only bundles (merges) text chunks, if its used to bundle CSS, the bundle might have duplicate entries (chunks can be duplicate free but when merged, duplicate CSS can be created).
@@ -19,12 +17,6 @@ Using npm:
 $ npm install --save-dev optimize-css-assets-webpack-plugin
 ```
 
-If you are not going to specify a CSS processor you will also need to install [cssnano](http://github.com/ben-eb/cssnano) (since it's a peer dependency):
-
-```shell
-$ npm install --save-dev cssnano
-```
-
 ## Configuration:
 
 The plugin can receive the following options (all of them are optional):

index.js

@@ -1,5 +1,4 @@
-var _ = require('underscore');
-var webpackSources = require('webpack-sources');
+var LastCallWebpackPlugin = require('last-call-webpack-plugin');
 
 function OptimizeCssAssetsPlugin(options) {
   this.options = options || {};
@@ -19,84 +18,30 @@ function OptimizeCssAssetsPlugin(options) {
   if (this.options.canPrint === undefined) {
     this.options.canPrint = true;
   }
-};
-
-OptimizeCssAssetsPlugin.prototype.print = function() {
-  if (this.options.canPrint) {
-    console.log.apply(console, arguments);
-  }
-};
 
-OptimizeCssAssetsPlugin.prototype.processCss = function(css, assetName) {
-  return this.options.cssProcessor.process(css, Object.assign({ to: assetName }, this.options.cssProcessorOptions));
+  var self = this;
+  this.lastCallInstance = new LastCallWebpackPlugin({
+    assetProcessors: [
+      {
+        regExp: this.options.assetNameRegExp,
+        processor: function (assetName, asset) {
+          return self.processCss(assetName, asset);
+        },
+      }
+    ],
+    canPrint: this.options.canPrint
+  });
 };
 
-OptimizeCssAssetsPlugin.prototype.createCssAsset = function(css, originalAsset) {
-  return new webpackSources.RawSource(css);
+OptimizeCssAssetsPlugin.prototype.processCss = function(assetName, asset) {
+  var css = asset.source();
+  return this.options
+    .cssProcessor.process(css, Object.assign({ to: assetName }, this.options.cssProcessorOptions))
+    .then(r => r.css);
 };
 
 OptimizeCssAssetsPlugin.prototype.apply = function(compiler) {
-
-  var self = this;
-
-  compiler.plugin('emit', function(compilation, compileCallback) {
-
-    self.print('\nStarting to optimize CSS...');
-
-    var assets = compilation.assets;
-
-    var cssAssetNames = _.filter(
-      _.keys(assets),
-      function(assetName) {
-        return assetName.match(self.options.assetNameRegExp);
-      }
-    );
-
-    var hasErrors = false;
-    var promises = [];
-
-    _.each(
-      cssAssetNames,
-      function(assetName) {
-
-        self.print('Processing ' + assetName + '...');
-
-        var asset = assets[assetName];
-
-        var originalCss = asset.source();
-
-        var promise = self
-          .processCss(originalCss, assetName)
-          .then(
-            function (result) {
-
-              if (hasErrors) {
-                self.print('Skiping ' + assetName + ' because of an error.');
-                return;
-              }
-
-              var processedCss = result.css;
-
-              assets[assetName] = self.createCssAsset(processedCss, asset);
-
-              self.print('Processed ' + assetName + ', before: ' + originalCss.length + ', after: ' + processedCss.length + ', ratio: ' + (Math.round(((processedCss.length * 100) / originalCss.length) * 100) / 100) + '%');
-
-            }
-          ).catch(function(err) {
-              hasErrors = true;
-              self.print('Error processing file: ' + assetName);
-              throw err;
-            }
-          );
-
-        promises.push(promise);
-      }
-    );
-
-    Promise.all(promises)
-      .then(function () { compileCallback(); })
-      .catch(compileCallback);
-  });
+  return this.lastCallInstance.apply(compiler);
 };
 
 module.exports = OptimizeCssAssetsPlugin;

package.json

@@ -4,11 +4,8 @@
   "author": "Nuno Rodrigues",
   "description": "A Webpack plugin to optimize \\ minimize CSS assets.",
   "dependencies": {
-    "underscore": "^1.8.3",
-    "webpack-sources": "^0.1.0"
-  },
-  "peerDependencies": {
-    "cssnano": ">=3.4.0"
+    "cssnano": "^3.4.0",
+    "last-call-webpack-plugin": "^2.0.1"
   },
   "main": "index.js",
   "homepage": "http://github.com/NMFR/optimize-css-assets-webpack-plugin",