fix: Purgecss webpack plugin/only filter fix (#933)

* fix: check if file exists in chunk after only filter

* test: update simple-with-exclusion test case of purgecss-webpack-plugin to actually test for purgecss exclusion

* docs: only option checks against chunk names instead of entrypoints

docs/plugins/webpack.md

@@ -7,7 +7,7 @@ meta:
   - itemprop: description
     content: PurgeCSS is a tool for removing CSS that you're not actually using in your project. You can use it with webpack with a plugin.
   - property: og:url
-    content:  https://purgecss.com/plugins/webpack
+    content: https://purgecss.com/plugins/webpack
   - property: og:site_name
     content: purgecss.com
   - property: og:type
@@ -39,55 +39,54 @@ npm i purgecss-webpack-plugin -D
 ### With mini-css-extract-plugin
 
 ```js
-const path = require('path')
-const glob = require('glob')
-const MiniCssExtractPlugin = require('mini-css-extract-plugin')
-const PurgecssPlugin = require('purgecss-webpack-plugin')
+const path = require("path");
+const glob = require("glob");
+const MiniCssExtractPlugin = require("mini-css-extract-plugin");
+const PurgecssPlugin = require("purgecss-webpack-plugin");
 
 const PATHS = {
-  src: path.join(__dirname, 'src')
-}
+  src: path.join(__dirname, "src"),
+};
 
 module.exports = {
-  entry: './src/index.js',
+  entry: "./src/index.js",
   output: {
-    filename: 'bundle.js',
-    path: path.join(__dirname, 'dist')
+    filename: "bundle.js",
+    path: path.join(__dirname, "dist"),
   },
   optimization: {
     splitChunks: {
       cacheGroups: {
         styles: {
-          name: 'styles',
+          name: "styles",
           test: /\.css$/,
-          chunks: 'all',
-          enforce: true
-        }
-      }
-    }
+          chunks: "all",
+          enforce: true,
+        },
+      },
+    },
   },
   module: {
     rules: [
       {
         test: /\.css$/,
-        use: [
-          MiniCssExtractPlugin.loader,
-          "css-loader"
-        ]
-      }
-    ]
+        use: [MiniCssExtractPlugin.loader, "css-loader"],
+      },
+    ],
   },
   plugins: [
     new MiniCssExtractPlugin({
       filename: "[name].css",
     }),
     new PurgecssPlugin({
-      paths: glob.sync(`${PATHS.src}/**/*`,  { nodir: true }),
+      paths: glob.sync(`${PATHS.src}/**/*`, { nodir: true }),
     }),
-  ]
-}
+  ],
+};
 ```
+
 ### Multiple paths
+
 If you need multiple paths use the npm package `glob-all` instead of `glob`, then you can use this syntax:
 
 ```js
@@ -97,70 +96,70 @@ new PurgecssPlugin({
   ])
 }),
 ```
+
 to filter out directories see the glob-all documentation [here](https://www.npmjs.com/package/glob-all#filtering-out-directories).
 
 ## Options
 
 The options available in purgecss [Configuration](https://www.purgecss.com/configuration.html) are also available in the webpack plugin, with the exception of the `css` and `content` options.
 
-* #### paths
+- #### paths
 
 With the webpack plugin, you can specify the content that should be analyzed by purgecss by providing an array of filenames. These can be html, pug, blade, ... files. You can also use a module like `glob` or `glob-all` to easily get a list of files.
 
 > You likely need to pass `{ noDir: true }` as an option to `glob.sync()` as `glob.sync` is matching a dir which the plugin can't operate on.
 
 ```js
-const PurgecssPlugin = require('purgecss-webpack-plugin')
-const glob = require('glob')
+const PurgecssPlugin = require("purgecss-webpack-plugin");
+const glob = require("glob");
 const PATHS = {
-  src: path.join(__dirname, 'src')
-}
+  src: path.join(__dirname, "src"),
+};
 
 // In the webpack configuration
 new PurgecssPlugin({
-  paths: glob.sync(`${PATHS.src}/**/*`, { nodir: true })
-})
+  paths: glob.sync(`${PATHS.src}/**/*`, { nodir: true }),
+});
 ```
 
 If you want to regenerate the list of paths on every compilation (e.g. when using `--watch`), then you can also pass a function to the `paths` option as in the following example:
 
 ```js
 new PurgecssPlugin({
-  paths: () => glob.sync(`${PATHS.src}/**/*`, { nodir: true })
-})
+  paths: () => glob.sync(`${PATHS.src}/**/*`, { nodir: true }),
+});
 ```
 
-* #### only
+- #### only
 
-You can specify entrypoints to the purgecss-webpack-plugin with the option `only`:
+You can specify chunk names to the purgecss-webpack-plugin with the option `only`:
 
 ```js
 new PurgecssPlugin({
   paths: glob.sync(`${PATHS.src}/**/*`, { nodir: true }),
-  only: ['bundle', 'vendor']
-})
+  only: ["bundle", "vendor"],
+});
 ```
 
-* #### safelist
+- #### safelist
 
 Similar as for the `paths` option, you also can define a function for this option:
 
 ```js
 function collectSafelist() {
   return {
-    standard: ['safelisted', /^safelisted-/],
+    standard: ["safelisted", /^safelisted-/],
     deep: [/^safelisted-deep-/],
-    greedy: [/^safelisted-greedy/]
-  }
+    greedy: [/^safelisted-greedy/],
+  };
 }
 
 // In the webpack configuration
 new PurgeCSSPlugin({
-  safelist: collectSafelist
-})
+  safelist: collectSafelist,
+});
 ```
 
-
-* #### rejected
+- #### rejected
 
 When this option is set to `true` all removed selectors are added to the [Stats Data](https://webpack.js.org/api/stats/) as `purged`.

packages/purgecss-webpack-plugin/__tests__/cases/simple-with-exclusion/expected/styles.css → packages/purgecss-webpack-plugin/__tests__/cases/simple-with-exclusion/expected/bundle.css

@@ -5,30 +5,10 @@
   color: red;
 }
 
-.unused {
-  color: blue;
-}
-
 .safelisted {
   color: green;
 }
 
 md\:w-2\/3 {
   color: red;
 }
-
-/*!******************************************************************************!*\
-  !*** css ../../../../../node_modules/css-loader/dist/cjs.js!./src/style.css ***!
-  \******************************************************************************/
-.legacy-unused-class {
-  color: red;
-}
-
-.unused-too {
-  color: blue;
-}
-
-.hello {
-  color: red;
-}
-

packages/purgecss-webpack-plugin/__tests__/cases/simple-with-exclusion/expected/legacy.css

@@ -0,0 +1,14 @@
+/*!******************************************************************************!*\
+  !*** css ../../../../../node_modules/css-loader/dist/cjs.js!./src/style.css ***!
+  \******************************************************************************/
+.legacy-unused-class {
+  color: red;
+}
+
+.unused-too {
+  color: blue;
+}
+
+.hello {
+  color: red;
+}

packages/purgecss-webpack-plugin/__tests__/cases/simple-with-exclusion/webpack.config.js

@@ -1,7 +1,7 @@
 const path = require("path");
 const glob = require("glob");
 const MiniCssExtractPlugin = require("mini-css-extract-plugin");
-const {PurgeCSSPlugin} = require("../../../src/");
+const { PurgeCSSPlugin } = require("../../../src/");
 
 const customExtractor = (content) => content.match(/[A-z0-9-:/]+/g) || [];
 
@@ -17,17 +17,7 @@ module.exports = {
     legacy: "./src/legacy.js",
   },
   optimization: {
-    splitChunks: {
-      cacheGroups: {
-        styles: {
-          name: "styles",
-          type: "css/mini-extract",
-          test: /\.css$/,
-          chunks: "all",
-          enforce: true,
-        },
-      },
-    },
+    splitChunks: { chunks: "all" },
   },
   module: {
     rules: [

packages/purgecss-webpack-plugin/src/index.ts

@@ -167,7 +167,9 @@ export class PurgeCSSPlugin {
     for (const chunk of compilation.chunks) {
       const assetsToPurge = assetsFromCompilation.filter(([name]) => {
         if (this.options.only) {
-          return this.options.only.some((only) => name.includes(only));
+          if (!(this.options.only.some((only) => name.includes(only)))) {
+            return false;
+          }
         }
 
         return chunk.files.has(name);