feat(plugins/url): add url() filter support (options.url) (webpack-contrib#655)

Author: michael-ciniawsky

README.md

@@ -74,6 +74,7 @@ export default `
   }
 `
 ```
+
 #### `{Boolean}`
 
 To disable `url()` resolving by `css-loader` set the option to `false`
@@ -88,6 +89,32 @@ To disable `url()` resolving by `css-loader` set the option to `false`
 }
 ```
 
+#### `{RegExp}`
+
+**webpack.config.js**
+```js
+{
+  loader: 'css-loader',
+  options: {
+    url: /filter/
+  }
+}
+```
+
+#### `{Function}`
+
+**webpack.config.js**
+```js
+{
+  loader: 'css-loader',
+  options: {
+    url (url) {
+      return /filter/.test(url)
+    }
+  }
+}
+```
+
 ### `import`
 
 ```css

src/index.js

@@ -9,7 +9,7 @@ import { getOptions } from 'loader-utils';
 import validateOptions from 'schema-utils';
 
 import postcss from 'postcss';
-// TODO(michael-ciniawsky) 
+// TODO(michael-ciniawsky)
 // replace with postcss-icss-{url, import}
 import urls from './plugins/url';
 import imports from './plugins/import';
@@ -26,15 +26,12 @@ const DEFAULTS = {
   sourceMap: false,
 };
 
-export default function loader (css, map, meta) {
+export default function loader(css, map, meta) {
   // Loader Options
-  const options = Object.assign(
-    {}, 
-    DEFAULTS, 
-    getOptions(this)
-  );
+  const options = Object.assign({}, DEFAULTS, getOptions(this));
 
   validateOptions(schema, options, 'CSS Loader');
+
   // Loader Mode (Async)
   const cb = this.async();
   const file = this.resourcePath;
@@ -47,14 +44,13 @@ export default function loader (css, map, meta) {
     map = false;
   }
 
-  // CSS Plugins
   const plugins = [];
 
   // URL Plugin
   if (options.url) {
-    plugins.push(urls());
+    plugins.push(urls(options));
   }
-  
+
   // Import Plugin
   if (options.import) {
     plugins.push(imports());
@@ -64,7 +60,7 @@ export default function loader (css, map, meta) {
   if (options.minimize) {
     plugins.push(minifier());
   }
-    
+
   if (meta) {
     const { ast } = meta;
     // Reuse CSS AST (PostCSS AST e.g 'postcss-loader')
@@ -73,34 +69,33 @@ export default function loader (css, map, meta) {
       css = ast.root;
     }
   }
-   
-  map = options.sourceMap 
+
+  map = options.sourceMap
     ? {
-      prev: map || false,
-      inline: false,
-      annotation: false,
-      sourcesContent: true,
-    }
-    : false
-  
+        prev: map || false,
+        inline: false,
+        annotation: false,
+        sourcesContent: true,
+      }
+    : false;
+
   return postcss(plugins)
     .process(css, {
       from: `/css-loader!${file}`,
       map,
       to: file,
-    }).then(({ css, map, messages }) => {
+    })
+    .then(({ css, map, messages }) => {
       if (meta && meta.messages) {
-        messages = messages.concat(meta.messages)
+        messages = messages.concat(meta.messages);
       }
-      
+
       // CSS Imports
       const imports = messages
-        .filter((msg) => msg.type === 'import' ? msg : false)
+        .filter((msg) => (msg.type === 'import' ? msg : false))
         .reduce((imports, msg) => {
           try {
-            msg = typeof msg.import === 'function' 
-              ? msg.import()
-              : msg.import;
+            msg = typeof msg.import === 'function' ? msg.import() : msg.import;
 
             imports += msg;
           } catch (err) {
@@ -109,17 +104,15 @@ export default function loader (css, map, meta) {
             this.emitError(err);
           }
 
-          return imports
-        }, '')
-      
+          return imports;
+        }, '');
+
       // CSS Exports
       const exports = messages
-        .filter((msg) => msg.type === 'export' ? msg : false)
-        .reduce((exports, msg) => { 
-          try {      
-            msg = typeof msg.export === 'function' 
-              ? msg.export()
-              : msg.export;
+        .filter((msg) => (msg.type === 'export' ? msg : false))
+        .reduce((exports, msg) => {
+          try {
+            msg = typeof msg.export === 'function' ? msg.export() : msg.export;
 
             exports += msg;
           } catch (err) {
@@ -129,23 +122,27 @@ export default function loader (css, map, meta) {
           }
 
           return exports;
-        }, '')
-      
-      // TODO(michael-ciniawsky) 
+        }, '');
+
+      // TODO(michael-ciniawsky)
       // triage if and add CSS runtime back
       const result = [
         imports ? `// CSS Imports\n${imports}\n` : false,
         exports ? `// CSS Exports\n${exports}\n` : false,
-        `// CSS\nexport default \`${css}\``
+        `// CSS\nexport default \`${css}\``,
       ]
         .filter(Boolean)
         .join('\n');
-  
+
       cb(null, result, map ? map.toJSON() : null);
 
       return null;
     })
     .catch((err) => {
-      err.name === 'CssSyntaxError' ? cb(new SyntaxError(err)) : cb(err);
+      err = err.name === 'CssSyntaxError' ? new SyntaxError(err) : err;
+
+      cb(err);
+
+      return null;
     });
-};
+}

src/options.json

@@ -2,7 +2,12 @@
   "type": "object",
   "properties": {
     "url": {
-      "type": "boolean"
+      "anyOf": [
+        { "type": "string" },
+        { "type": "boolean" },
+        { "instanceof": "RegExp" },
+        { "instanceof": "Function" }
+      ]
     },
     "import": {
       "type": "boolean"

src/plugins/url.js

@@ -1,18 +1,16 @@
 /* eslint-disable */
 import postcss from 'postcss';
 import valueParser from 'postcss-value-parser';
-// ICSS {String}
-// import { createICSSRules } from "icss-utils";
 
-const walkUrls = (parsed, callback) => {
+const walkUrls = (parsed, cb) => {
   parsed.walk((node) => {
     if (node.type === 'function' && node.value === 'url') {
       const content = node.nodes.length !== 0 && node.nodes[0].type === 'string'
         ? node.nodes[0].value
         : valueParser.stringify(node.nodes);
 
       if (content.trim().length !== 0) {
-        callback(node, content);
+        cb(node, content);
       }
 
       // do not traverse inside url
@@ -22,30 +20,32 @@ const walkUrls = (parsed, callback) => {
 };
 
 const mapUrls = (parsed, map) => {
-  walkUrls(parsed, (node, content) => {
-    node.nodes = [{ type: 'word', value: map(content) }];
+  walkUrls(parsed, (node, url) => {
+    node.nodes = [{ type: 'word', value: map(url) }];
   });
 };
 
-const filterUrls = (parsed, filter) => {
+const filterUrls = (parsed, filter, options) => {
   const result = [];
 
-  walkUrls(parsed, (node, content) => {
-    if (filter(content)) {
-      result.push(content);
+  walkUrls(parsed, (node, url) => {
+    if (filter(url, options)) {
+      return false
     }
+    
+    return result.push(url);
   });
 
   return result;
 };
 
-const walkDeclsWithUrl = (css, filter) => {
+const walkDeclsWithUrl = (css, filter, options) => {
   const result = [];
 
   css.walkDecls((decl) => {
     if (decl.value.includes('url(')) {
       const parsed = valueParser(decl.value);
-      const values = filterUrls(parsed, filter);
+      const values = filterUrls(parsed, filter, options);
 
       if (values.length) {
         result.push({
@@ -60,10 +60,39 @@ const walkDeclsWithUrl = (css, filter) => {
   return result;
 };
 
-const filterValues = value => !/^\w+:\/\//.test(value) &&
-    !value.startsWith('//') &&
-    !value.startsWith('#') &&
-    !value.startsWith('data:');
+const URL = /^\w+:\/\//;
+
+const filter = (url, options) => {
+  if (URL.test(url)) {
+    return true;
+  }
+
+  if (url.startsWith('//')) {
+    return true;
+  }
+
+  if (url.startsWith('//')) {
+    return true;
+  }
+
+  if (url.startsWith('#')) {
+    return true;
+  }
+  
+  if (url.startsWith('data:')) {
+    return true;
+  }
+
+  if (options.url instanceof RegExp) {
+    return options.url.test(url);
+  }
+
+  if (typeof options.url === 'function') {
+    return options.url(url);
+  }
+
+  return false;
+}
 
 const flatten = arr => arr.reduce((acc, d) => [...acc, ...d], []);
 
@@ -72,24 +101,23 @@ const uniq = arr => arr.reduce(
   [],
 );
 
-module.exports = postcss.plugin('postcss-icss-url', () => (css, result) => {
-  const traversed = walkDeclsWithUrl(css, filterValues);
+module.exports = postcss.plugin('postcss-icss-url', (options) => (css, result) => {
+  const traversed = walkDeclsWithUrl(css, filter, options);
   const paths = uniq(flatten(traversed.map(item => item.values)));
 
-  // ICSS imports {String}
   const aliases = {};
 
   paths.forEach((url, idx) => {
-    // ICSS Placeholder
+    // CSS Content Placeholder
     const alias = '${' + `CSS__URL__${idx}` + '}';
-
+    
     aliases[url] = alias;
 
     result.messages.push({
       type: 'import',
       plugin: 'postcss-icss-url',
       import: `import CSS__URL__${idx} from '${url}';\n`
-    })
+    });
   });
 
   traversed.forEach((item) => {
@@ -98,3 +126,4 @@ module.exports = postcss.plugin('postcss-icss-url', () => (css, result) => {
     item.decl.value = item.parsed.toString();
   });
 });
+

test/fixtures/imports/fixture.js

@@ -1 +1,3 @@
 import css from './fixture.css';
+
+export default css;

test/fixtures/urls/file.css

@@ -0,0 +1,3 @@
+.url {
+  background: url('./file.png') 
+}

test/fixtures/urls/filter/fixture.css

@@ -0,0 +1,4 @@
+.url {
+  background: url('./file.png');
+  background: url('./filter/file.png');
+}

test/fixtures/urls/filter/fixture.js

@@ -0,0 +1,3 @@
+import css from './fixture.css';
+
+export default css;

test/fixtures/urls/fixture.js

@@ -1 +1,3 @@
 import css from './fixture.css';
+
+export default css;

test/loader.test.js

@@ -14,7 +14,7 @@ describe('Loader', () => {
 
     const stats = await webpack('fixture.js', config);
     const { source } = stats.toJson().modules[1];
-        
+
     expect(source).toMatchSnapshot();
   });
 });