improve dev server compile error handling

Author: yyx990803

build/setup-dev-server.js

@@ -4,6 +4,12 @@ const MFS = require('memory-fs')
 const clientConfig = require('./webpack.client.config')
 const serverConfig = require('./webpack.server.config')
 
+const readFile = (fs, file) => {
+  try {
+    return fs.readFileSync(path.join(clientConfig.output.path, file), 'utf-8')
+  } catch (e) {}
+}
+
 module.exports = function setupDevServer (app, cb) {
   let bundle, clientManifest
   let resolve
@@ -28,10 +34,16 @@ module.exports = function setupDevServer (app, cb) {
     noInfo: true
   })
   app.use(devMiddleware)
-  clientCompiler.plugin('done', () => {
-    const fs = devMiddleware.fileSystem
-    const readFile = file => fs.readFileSync(path.join(clientConfig.output.path, file), 'utf-8')
-    clientManifest = JSON.parse(readFile('vue-ssr-client-manifest.json'))
+  clientCompiler.plugin('done', stats => {
+    stats = stats.toJson()
+    stats.errors.forEach(err => console.error(err))
+    stats.warnings.forEach(err => console.warn(err))
+    if (stats.errors.length) return
+
+    clientManifest = JSON.parse(readFile(
+      devMiddleware.fileSystem,
+      'vue-ssr-client-manifest.json'
+    ))
     if (bundle) {
       ready(bundle, {
         clientManifest
@@ -49,12 +61,10 @@ module.exports = function setupDevServer (app, cb) {
   serverCompiler.watch({}, (err, stats) => {
     if (err) throw err
     stats = stats.toJson()
-    stats.errors.forEach(err => console.error(err))
-    stats.warnings.forEach(err => console.warn(err))
-    const readFile = file => mfs.readFileSync(path.join(clientConfig.output.path, file), 'utf-8')
+    if (stats.errors.length) return
 
     // read bundle generated by vue-ssr-webpack-plugin
-    bundle = JSON.parse(readFile('vue-ssr-server-bundle.json'))
+    bundle = JSON.parse(readFile(mfs, 'vue-ssr-server-bundle.json'))
     if (clientManifest) {
       ready(bundle, {
         clientManifest