simplify cssModules injection

Author: yyx990803

lib/component-normalizer.js

@@ -29,24 +29,10 @@ module.exports = function normalizeComponent (
   }
 
   if (injectStyles) {
-    var injected = false
-    var cssModules
-    var inject = function () {
-      if (!injected) {
-        injected = true
-        cssModules = injectStyles()
-      }
-      // inject cssModules
-      if (cssModules) {
-        for (var key in cssModules) {
-          this[key] = cssModules[key]
-        }
-      }
-    }
     var existing = options.beforeCreate
     options.beforeCreate = existing
-      ? [].concat(existing, inject)
-      : [inject]
+      ? [].concat(existing, injectStyles)
+      : [injectStyles]
   }
 
   // scopedId

lib/loader.js

@@ -281,13 +281,10 @@ module.exports = function (content) {
   var parts = parse(content, fileName, this.sourceMap)
   var hasScoped = parts.styles.some(function (s) { return s.scoped })
 
-  // css modules
-  var cssModules
-
   // add requires for styles
   if (parts.styles.length) {
     var styleInjectionCode = 'function __injectVueStyle__ () {\n'
-    var hasModules = false
+    var cssModules = {}
     parts.styles.forEach(function (style, i) {
       // require style
       var requireString = style.src
@@ -297,13 +294,6 @@ module.exports = function (content) {
       var moduleName = (style.module === true) ? '$style' : style.module
       // setCssModule
       if (moduleName) {
-        if (!cssModules) {
-          cssModules = {}
-        }
-        if (!hasModules) {
-          hasModules = true
-          styleInjectionCode += 'var cssModules = {}\n'
-        }
         if (moduleName in cssModules) {
           loaderContext.emitError('CSS module name "' + moduleName + '" is not unique!')
           styleInjectionCode += requireString
@@ -317,15 +307,12 @@ module.exports = function (content) {
             requireString += '.locals'
           }
 
-          styleInjectionCode += 'cssModules["' + moduleName + '"] = ' + requireString + '\n'
+          styleInjectionCode += 'this["' + moduleName + '"] = ' + requireString + '\n'
         }
       } else {
         styleInjectionCode += requireString + '\n'
       }
     })
-    if (hasModules) {
-      styleInjectionCode += `return cssModules`
-    }
     styleInjectionCode += '}\n'
     output += styleInjectionCode
   }
@@ -449,22 +436,9 @@ module.exports = function (content) {
         '    hotAPI.createRecord("' + moduleId + '", Component.options)\n' +
         '  } else {\n'
       // update
-      if (cssModules) {
-        output +=
-        '    if (module.hot.data.cssModules && JSON.stringify(module.hot.data.cssModules) !== JSON.stringify(cssModules)) {\n' +
-        '      delete Component.options._Ctor\n' +
-        '    }\n'
-      }
       output +=
         '    hotAPI.reload("' + moduleId + '", Component.options)\n' +
         '  }\n'
-      if (cssModules) {
-        // save cssModules
-        output +=
-        '  module.hot.dispose(function (data) {\n' +
-        '    data.cssModules = cssModules\n' +
-        '  })\n'
-      }
       output += '})()}\n'
     }
     // final export