use simpler hot-reload mechanism

Author: yyx990803

lib/loader.js

@@ -177,38 +177,21 @@ module.exports = function (content) {
       process.env.NODE_ENV !== 'production' &&
       (parts.script.length || parts.template.length)
     ) {
-      var scriptString = parts.script.length ? getRequireString('script', parts.script[0], 0) : ''
-      var templateString = template
-        ? template.src
-          ? getRequireForImportString('template', template, hasLocalStyles)
-          : getRequireString('template', template, 0, hasLocalStyles)
-        : ''
-      var accepted = []
-      if (scriptString) {
-        accepted.push(scriptString.slice(1, -1))
-      }
-      if (templateString) {
-        accepted.push(templateString.slice(1, -1))
-      }
       output +=
-        'if (module.hot) {\n' +
-          '(function () {\n' +
-            // shim the component directive so that it
-            // registers the instances
-            'var hotAPI = require("vue-hot-reload-api")\n' +
-            'hotAPI.install(require("vue"))\n' +
-            'if (!hotAPI.compatible) return\n' +
-            'var id = ' + (scriptString || templateString) + '\n' +
-            // create the record
-            'hotAPI.createRecord(id, module.exports)\n' +
-            'module.hot.accept(' + JSON.stringify(accepted) + ', function () {\n' +
-              'var newOptions = ' + (scriptString ? 'require(' + scriptString + ')\n' : 'null\n') +
-              'if (newOptions && newOptions.__esModule) newOptions = newOptions.default\n' +
-              'var newTemplate = ' + (templateString ? 'require(' + templateString + ')\n' : 'null\n') +
-              'hotAPI.update(id, newOptions, newTemplate)\n' +
-            '})\n' +
-          '})()\n' +
-        '}'
+        'if (module.hot) {(function () {' +
+        '  module.hot.accept()\n' +
+        '  var hotAPI = require("vue-hot-reload-api")\n' +
+        '  hotAPI.install(require("vue"), true)\n' +
+        '  if (!hotAPI.compatible) return\n' +
+        '  var id = ' + JSON.stringify(filePath) + '\n' +
+        '  if (!module.hot.data) {\n' +
+        // initial insert
+        '    hotAPI.createRecord(id, module.exports)\n' +
+        '  } else {\n' +
+        // update
+        '    hotAPI.update(id, module.exports, (typeof module.exports === "function" ? module.exports.options : module.exports).template)\n' +
+        '  }\n' +
+        '})()}'
     }
 
     // done