enable css source mapping if devtool option is set

Author: yyx990803

lib/loader.js

@@ -38,6 +38,11 @@ module.exports = function (content) {
     defaultLoaders.js = 'babel-loader'
   }
 
+  // enable css source map if needed
+  if (this.sourceMap) {
+    defaultLoaders.css = 'style-loader!css-loader?sourceMap'
+  }
+
   // check if there are custom loaders specified via
   // webpack config, otherwise use defaults
   var loaders = assign({}, defaultLoaders, options.loaders)
@@ -92,12 +97,12 @@ module.exports = function (content) {
       }
       return injectString + ensureBang(loader)
     } else {
-      // unknown lang, assume a loader for it is used
+      // unknown lang, infer the loader to be used
       switch (type) {
         case 'template':
-          return 'vue-html!' + rewriter + 'template-html?raw&engine=' + lang + '!'
+          return defaultLoaders.html + '!' + rewriter + 'template-html-loader?raw&engine=' + lang + '!'
         case 'style':
-          return 'style!css!' + rewriter + lang + '!'
+          return defaultLoaders.css + '!' + rewriter + lang + '!'
         case 'script':
           return injectString + lang + '!'
       }

lib/style-rewriter.js

@@ -67,23 +67,25 @@ module.exports = function (css, map) {
   opts = {
     from: file,
     to: file,
-    map: {
+    map: this.sourceMap && {
       inline: false,
       annotation: false
     }
   }
-  if (map) {
+  if (map && opts.map) {
     opts.map.prev = map
   }
 
   currentId = query.id
   postcss(plugins)
     .process(css, opts)
     .then(function (result) {
-      var map = result.map.toJSON()
+      var map = result.map && result.map.toJSON()
       // ensure we give the style source a unique name
       // so that Webpack doesn't get confused
-      map.sources[0] = query.file + '.style'
+      if (map) {
+        map.sources[0] = query.file + '.style'
+      }
       cb(null, result.css, map)
     })
     .catch(function (e) {

test/test.js

@@ -153,8 +153,9 @@ describe('vue-loader', function () {
           var line
           var col
           var lines = code.split(/\r?\n/g)
+          var targetRE = /^\s+msg: 'Hello from Component A!'/
           lines.some(function (l, i) {
-            if (l.indexOf('Hello from Component A') > -1) {
+            if (targetRE.test(l)) {
               line = i
               col = lines[i - 1].length
               return true