Use Stylelint as a gatekeeper #508

.gitignore

@@ -0,0 +1,2 @@
+node_modules
+npm-debug.log

.stylelintrc

@@ -0,0 +1,34 @@
+{
+  "rules": {
+    "block-closing-brace-newline-after": "always",
+    "block-closing-brace-newline-before": "always",
+    "block-no-empty": true,
+    "block-opening-brace-newline-after": "always",
+    "block-opening-brace-space-before": "always",
+    "color-hex-case": "lower",
+    "color-hex-length": "short",
+    "color-no-invalid-hex": true,
+    "comment-empty-line-before": "always",
+    "comment-whitespace-inside": "always",
+    "declaration-block-no-single-line": true,
+    "declaration-block-semicolon-newline-after": "always",
+    "declaration-block-semicolon-space-before": "never",
+    "declaration-colon-space-after": "always",
+    "declaration-colon-space-before": "never",
+    "indentation": 2,
+    "max-empty-lines": 1,
+    "max-line-length": 80,
+    "no-eol-whitespace": true,
+    "no-missing-eof-newline": true,
+    "number-leading-zero": "always",
+    "number-no-trailing-zeros": true,
+    "rule-trailing-semicolon": "always",
+    "selector-combinator-space-after": "always",
+    "selector-combinator-space-before": "always",
+    "selector-list-comma-newline-after": "always",
+    "selector-list-comma-space-before": "never",
+    "string-quotes": "double",
+    "value-list-comma-space-after": "always",
+    "value-list-comma-space-before": "never"
+  }
+}

package.json

@@ -14,5 +14,11 @@
   },
   "main": "normalize.css",
   "author": "Nicolas Gallagher",
-  "license": "MIT"
+  "license": "MIT",
+  "devDependencies": {
+    "stylelint": "^4.2.0"
+  },
+  "scripts": {
+    "test": "stylelint normalize.css"
+  }
 }