support deps registered by postcss plugins

Author: yyx990803

lib/style-compiler/index.js

@@ -55,13 +55,20 @@ module.exports = function (css, map) {
 
     return postcss(plugins)
       .process(css, options)
-      .then(function (result) {
+      .then(result => {
+        if (result.messages) {
+          result.messages.forEach(m => {
+            if (m.type === 'dependency') {
+              this.addDependency(m.file)
+            }
+          })
+        }
         var map = result.map && result.map.toJSON()
         cb(null, result.css, map)
         return null // silence bluebird warning
       })
   }).catch(e => {
-    console.log(e)
+    console.error(e)
     cb(e)
   })
 }