Add unoptimized rule

README.md

@@ -42,6 +42,7 @@ Create the `.stylelintrc.json` config file (or open the existing one), add `styl
   "rules": {
     "images/broken": true,
     "images/prefer-data-uri": 256,
+    "images/unoptimized": true,
     ...
   }
 }
@@ -53,6 +54,7 @@ Please refer to [stylelint docs](http://stylelint.io/user-guide/) for the detail
 
 - [`broken`](./src/rules/broken/README.md): Checks if the images are broken.
 - [`prefer-data-uri`](./src/rules/prefer-data-uri/README.md): Suggest using data-URIs instead of an external image if their file size (in bytes) exceeds the limit.
+- [`unoptimized`](./src/rules/unoptimized/README.md): Checks if the images are unoptimized.
 
 ## Contribute
 

src/rules/index.js

@@ -1,7 +1,9 @@
 import broken from './broken';
 import preferDataURI from './prefer-data-uri';
+import unoptimized from './unoptimized';
 
 export default {
   broken,
-  'prefer-data-uri': preferDataURI
+  'prefer-data-uri': preferDataURI,
+  unoptimized
 };

src/rules/unoptimized/README.md

@@ -0,0 +1,12 @@
+# unoptimized
+
+Checks if the images are unoptimized (uses [imagemin](https://github.com/imagemin/imagemin)).
+
+## Options
+
+### `true`
+
+The following patterns are considered warnings:
+
+
+The following patterns are not considered warnings:

src/rules/unoptimized/index.js

@@ -0,0 +1,25 @@
+import { utils } from 'stylelint';
+import { namespace, generateListOfImagesURLsAndNodes, getImage } from '../../utils';
+
+export const ruleName = namespace('unoptimized');
+export const messages = utils.ruleMessages(ruleName, {
+  unexpected: imageURL => `Unexpected broken image "${imageURL}"`
+});
+
+export default function unoptimizedRule(enabled) {
+  return (root, result) => {
+    const validOptions = utils.validateOptions(result, ruleName, {
+      actual: enabled,
+      possible: [true, false]
+    });
+
+    if (!validOptions) {
+      return null;
+    }
+
+    const list = generateListOfImagesURLsAndNodes(root);
+
+    return checkIfImagesAreUnoptimized(list, result)
+      .then(results => reportUnoptimizedImages(results, result));
+  };
+}