add SSR support with test case

Author: YiSiWang

lib/loader.js

@@ -58,7 +58,7 @@ module.exports = function (content) {
   var bubleOptions = hasBuble && options.buble ? '?' + JSON.stringify(options.buble) : ''
   var defaultLoaders = {
     html: templateCompilerPath + '?id=' + moduleId,
-    css: styleLoaderPath + '!css-loader' + (needCssSourceMap ? '?sourceMap' : ''),
+    css: (isServer ? '' : styleLoaderPath + '!') + 'css-loader' + (needCssSourceMap ? '?sourceMap' : ''),
     js: hasBuble ? ('buble-loader' + bubleOptions) : hasBabel ? 'babel-loader' : ''
   }
 
@@ -177,21 +177,33 @@ module.exports = function (content) {
   var cssModules = {}
 
   // add requires for styles
-  if (!isServer && parts.styles.length) {
+  if (parts.styles.length) {
     output += '\n/* styles */\n'
     parts.styles.forEach(function (style, i) {
       /* !HACK! */
       style.module = i === 0 ? 'style' : '$style'
+
+      // require style
+      if (isServer && !style.module) return
       var requireString = style.src
         ? getRequireForImport('styles', style, style.scoped)
         : getRequire('styles', style, i, style.scoped)
+
       // setCssModule
       if (style.module) {
         if (style.module in cssModules) {
           loaderContext.emitError('CSS module name "' + style.module + '" is not unique!')
           output += requireString
         } else {
           cssModules[style.module] = true
+
+          // `style-loader` exposes the name-to-hash map directly
+          // `css-loader` exposes it in `.locals`
+          // We drop `style-loader` in SSR, and add `.locals` here.
+          if (isServer) {
+            requireString += '.locals'
+          }
+
           output += '__vue_styles__["' + style.module + '"] = ' + requireString + '\n'
         }
       } else {

test/fixtures/css-modules-ssr.js

@@ -0,0 +1,6 @@
+var Vue = require('vue')
+var App = require('./css-modules.vue')
+
+module.exports = function () {
+  return Promise.resolve(new Vue(App))
+}

test/test.js

@@ -427,21 +427,23 @@ describe('vue-loader', function () {
   })
 
   it.only('css-modules in SSR', function (done) {
-    test({
+    bundle({
       entry: './test/fixtures/css-modules.vue',
-      vue: {
-        target: 'node'
+      target: 'node',
+      output: Object.assign({}, globalConfig.output, {
+        libraryTarget: 'commonjs2'
+      })
+    }, function (code) {
+      // http://stackoverflow.com/questions/17581830/load-node-js-module-from-string-in-memory
+      function requireFromString(src, filename) {
+        var Module = module.constructor;
+        var m = new Module();
+        m._compile(src, filename);
+        return m.exports;
       }
-    }, function (window) {
-      var module = window.vueModule
-
-      // class name
-      var className = module.computed.style().red
-      expect(className).to.match(/^_/)
-
-      // no css
-      expect(window.document.querySelector('style')).to.not.exist()
 
+      var output = requireFromString(code, './test.build.js')
+      expect(output.computed.style().red).to.match(/^_/)
       done()
     })
   })