优化export; dev模式增加headers设置

lib/compile-vue.js

@@ -186,8 +186,16 @@ export function parseJs(
         if (isBuild) {
           name = name.replace(/\.vue$/, '.js')
         }
+        if (alias.trim() === '*') {
+          return `${t} ${alias} from '${name}'`
+        }
+        let _alias = alias
+        if (alias.includes('* as')) {
+          _alias = ' default ' + alias.replace('* as', '').trim()
+        }
+
         return `import ${alias} from '${name}'${
-          t === 'export' ? `\nexport ${alias}` : ''
+          t === 'export' ? `\nexport ${_alias}` : ''
         }`
       }
     )

lib/dev.js

@@ -42,6 +42,10 @@ export default async function createServer(root = '', conf = {}) {
     conf.imports['vue-router'] = conf.imports['vue-router-dev']
   }
 
+  if (conf.devServer.headers) {
+    Object.assign(COMMON_HEADERS, conf.devServer.headers)
+  }
+
   if (USE_HTTPS) {
     Object.assign(SERVER_OPTIONS, conf.devServer.ssl)