记录一个vue项目报错UnhandledPromiseRejectionWarning: Unhandled promise rejection.

使用vue-cli创建vue项目，加入一些之前的代码，然后打包运行报错：

(node:4892) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing insi
de of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection
 id: 1)
(node:4892) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections
 that are not handled will terminate the Node.js process with a non-zero exit code.
 // 然后加卡在这里不动了
18% building modules 72/73 modules 1 active ...ce-demo\weixin-vioce-demo\src\App.vue

网上查阅了很多的资料，下面是我整理的解决方案：

1. 在build文件夹下找到webpack.base.conf.js
   然后修改加入const vueLoaderPlugin = require(‘vue-loader/lib/plugin’)

'use strict'
const path = require('path')
const utils = require('./utils')
const config = require('../config')
const vueLoaderConfig = require('./vue-loader.conf')
//加入的
const vueLoaderPlugin = require('vue-loader/lib/plugin')

2. 在module.exports中引入 plugins:[new vueLoaderPlugin()]

 plugins:[
     new vueLoaderPlugin()
   ]

3. 下面是我的文件的完整代码

'use strict'
const path = require('path')
const utils = require('./utils')
const config = require('../config')
const vueLoaderConfig = require('./vue-loader.conf')
const vueLoaderPlugin = require('vue-loader/lib/plugin')

function resolve (dir) {
  return path.join(__dirname, '..', dir)
}
module.exports = {
  context: path.resolve(__dirname, '../'),
  entry: {
    app: './src/main.js'
  },
  output: {
    path: config.build.assetsRoot,
    filename: '[name].js',
    publicPath: process.env.NODE_ENV === 'production'
      ? config.build.assetsPublicPath
      : config.dev.assetsPublicPath
  },resolve: {
    extensions: ['.js', '.vue', '.json'],
    alias: {
      'vue$': 'vue/dist/vue.esm.js',
      '@': resolve('src'),
    }
  },
  module: {
    rules: [
      {
        test: /\.vue$/,
        loader: 'vue-loader',
        options: vueLoaderConfig
      },
      { test: /\.js$/,
        loader: 'babel-loader',
        include: [resolve('src'), resolve('test'), resolve('node_modules/webpack-dev-server/client')]
      },
      {
        test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 10000,
          name: utils.assetsPath('img/[name].[hash:7].[ext]')
        }
      },
      {test: /\.(mp4|webm|ogg|mp3|wav|flac|aac)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 10000,
          name: utils.assetsPath('media/[name].[hash:7].[ext]')
        }
      },
      {test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 10000,
          name: utils.assetsPath('fonts/[name].[hash:7].[ext]')
        }
      },
      {
        test: /\.sass$/,
        loaders: ['style', 'css', 'sass']
      },{
        test:/\.style$/,
        use:['style-loader','css-loader']
      }
    ]
  },
  node: {
    // prevent webpack from injecting useless setImmediate polyfill because Vue
    // source contains it (although only uses it if it's native).
    setImmediate: false,
    // prevent webpack from injecting mocks to Node native modules
    // that does not make sense for the client
    dgram: 'empty',
    fs: 'empty',
    net: 'empty',
    tls: 'empty',
    child_process: 'empty'
  },
  plugins:[
    new vueLoaderPlugin()
  ]
}

当以上解决之后再运行项目一般来说已经可以了，但是我这个项目还不行，继续其他错误

$ webpack-dev-server --inline --progress --config build/webpack.dev.conf.js
internal/modules/cjs/loader.js:638
    throw err;  
 	^
Error: Cannot find module 'vue-loader/lib/plugin'
 at Function.Module._resolveFilename (internal/modules/cjs/loader.js:636:15)
    at Function.Module._load (internal/modules/cjs/loader.js:562:25)
    at Module.require (internal/modules/cjs/loader.js:690:17) at require (internal/modules/cjs/helpers.js:25:18)
    at Object.<anonymous> (D:\HBuilderProjects\baidu-vioce-demo\weixin-vioce-demo\build\webpack.base.conf.js:6:25)
    at Module._compile (internal/modules/cjs/loader.js:776:30)at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)

这种错误其实网上有很多解决方法
主要的就是将对应的版本更新一下，就是对应的vue-loader这个插件的lib下面没有对应的plugin文件，具体做法：
升级了一下 “vue-loader”: “^15.7.0” 就好了

真棒！！