Adds analysis for empty rulesets (#48)

Author: bartveneman

readme.md

@@ -96,7 +96,10 @@ analyze('foo {}')
 //     unique: []
 //   },
 //   rules: {
-//     total: 1
+//     total: 1,
+//     empty: {
+//       total: 1
+//     }
 //   },
 //   selectors: {
 //     accessibility: {

src/analyzer/rules/index.js

@@ -1,7 +1,15 @@
+const isEmpty = rule => {
+  return rule.declarationsCount === 0
+}
+
 module.exports = rules => {
   const all = rules
+  const empty = rules.filter(isEmpty)
 
   return {
-    total: all.length
+    total: all.length,
+    empty: {
+      total: empty.length
+    }
   }
 }

src/parser/index.js

@@ -16,8 +16,9 @@ function processNodes(tree) {
 module.exports = css => {
   return new Promise(async (resolve, reject) => {
     try {
-      const result = await postcss().process(css, {from: undefined})
-      resolve(processNodes(result.root))
+      const result = await postcss.parse(css)
+      const rootNode = result.toResult().root
+      resolve(processNodes(rootNode))
     } catch (err) {
       const {source, line, column, reason} = err
       reject(new SyntaxError(

test/analyzer/index.js

@@ -79,7 +79,10 @@ test('Returns the correct analysis object structure', async t => {
       unique: []
     },
     rules: {
-      total: 1
+      total: 1,
+      empty: {
+        total: 1
+      }
     },
     selectors: {
       accessibility: {

test/analyzer/rules/input.css

@@ -11,3 +11,17 @@
     }
   }
 }
+
+/**
+ * Empty rule and at-rule
+ */
+.empty {}
+.empty-multiline{
+
+
+}
+@media screen {}
+
+@media (min-width: 1px) {
+  .empty-inside-mq {}
+}

test/analyzer/rules/output.json

@@ -1,3 +1,6 @@
 {
-  "total": 2
+  "total": 5,
+  "empty": {
+    "total": 3
+  }
 }