fix: better version check, closes #1564

packages/@vue/cli/bin/vue.js

@@ -1,20 +1,28 @@
 #!/usr/bin/env node
 
+// Check node version before requiring/doing anything else
+// The user may be on a very old node version
+
+const chalk = require('chalk')
+const semver = require('semver')
+const requiredVersion = require('../package.json').engines.node
+
+function checkNodeVersion (wanted, id) {
+  if (!semver.satisfies(process.version, wanted)) {
+    console.log(chalk.red(
+      'You are using Node ' + process.version + ', but this version of ' + id +
+      'requires Node ' + wanted + '.\nPlease upgrade your Node version.'
+    ))
+    process.exit(1)
+  }
+}
+
+checkNodeVersion(requiredVersion, 'vue-cli')
+
 const fs = require('fs')
 const path = require('path')
 const slash = require('slash')
-const chalk = require('chalk')
-const semver = require('semver')
 const minimist = require('minimist')
-const requiredVersion = require('../package.json').engines.node
-
-if (!semver.satisfies(process.version, requiredVersion)) {
-  console.log(chalk.red(
-    `You are using Node ${process.version}, but this version of vue-cli ` +
-    `requires Node ${requiredVersion}.\nPlease upgrade your Node version.`
-  ))
-  process.exit(1)
-}
 
 // enter debug mode when creating test repo
 if (
@@ -105,6 +113,7 @@ program
   .option('--headless', `Don't open browser on start and output port`)
   .description('start and open the vue-cli ui')
   .action((cmd) => {
+    checkNodeVersion('>=8.6', 'vue ui')
     require('../lib/ui')(cleanArgs(cmd))
   })
 
@@ -135,17 +144,7 @@ program.on('--help', () => {
 program.commands.forEach(c => c.on('--help', () => console.log()))
 
 // enhance common error messages
-const enhanceErrorMessages = (methodName, log) => {
-  program.Command.prototype[methodName] = function (...args) {
-    if (methodName === 'unknownOption' && this._allowUnknownOption) {
-      return
-    }
-    this.outputHelp()
-    console.log(`  ` + chalk.red(log(...args)))
-    console.log()
-    process.exit(1)
-  }
-}
+const enhanceErrorMessages = require('../lib/util/enhanceErrorMessages')
 
 enhanceErrorMessages('missingArgument', argName => {
   return `Missing required argument ${chalk.yellow(`<${argName}>`)}.`

packages/@vue/cli/lib/util/enhanceErrorMessages.js

@@ -0,0 +1,14 @@
+const program = require('commander')
+const chalk = require('chalk')
+
+module.exports = (methodName, log) => {
+  program.Command.prototype[methodName] = function (...args) {
+    if (methodName === 'unknownOption' && this._allowUnknownOption) {
+      return
+    }
+    this.outputHelp()
+    console.log(`  ` + chalk.red(log(...args)))
+    console.log()
+    process.exit(1)
+  }
+}