缺失文件补充

build/index.js

+const { run } = require('runjs')
+const chalk = require('chalk')
+const config = require('../vue.config.js')
+const rawArgv = process.argv.slice(2)
+const args = rawArgv.join(' ')
+
+if (process.env.npm_config_preview || rawArgv.includes('--preview')) {
+  const report = rawArgv.includes('--report')
+
+  run(`vue-cli-service build ${args}`)
+
+  const port = 9526
+  const publicPath = config.publicPath
+
+  var connect = require('connect')
+  var serveStatic = require('serve-static')
+  const app = connect()
+
+  app.use(
+    publicPath,
+    serveStatic('./dist', {
+      index: ['index.html', '/']
+    })
+  )
+
+  app.listen(port, function () {
+    console.log(chalk.green(`> Preview at  http://localhost:${port}${publicPath}`))
+    if (report) {
+      console.log(chalk.green(`> Report at  http://localhost:${port}${publicPath}report.html`))
+    }
+
+  })
+} else {
+  run(`vue-cli-service build ${args}`)
+}