"vue-cli-service serve" 文件运行及process.env.NODE_ENV

node_modules > @vue > cli-service > lib > commands > serve.js

//设置服务器host及port
const defaults = {
  host: '0.0.0.0',
  port: 8080,
  https: false
}

//文件输出运行....
module.exports = (api, options) => {
  //查看api对象属性，如下码所示
  console.log(api)
  api.registerCommand('serve', {
  ......

api对象属性，如下码所示

PluginAPI {
  id: 'built-in:commands/serve',
  service:
   Service {
     initialized: true,
     context: 'path/works/vue-cli2/hello-world',
     inlineOptions: undefined,
     webpackChainFns: [],
     webpackRawConfigFns: [],
     devServerConfigFns: [],
     commands: {},
     pkgContext: 'path/works/vue-cli2/hello-world',
     pkg:
      { name: 'hello-world',
        version: '0.1.0',
        private: true,
        scripts: [Object],
        dependencies: [Object],
        devDependencies: [Object],
        eslintConfig: [Object],
        browserslist: [Array],
        readme: 'ERROR: No README data found!',
        _id: '[email protected]' },
     plugins:
      [ [Object],
        [Object],
        [Object],
        [Object],
        [Object],
        [Object],
        [Object],
        [Object],
        [Object],
        [Object] ],
     pluginsToSkip: Set {},
     modes:
      { serve: 'development',
        build: 'production',
        inspect: 'development' },
     mode: 'development',
     projectOptions:
      { publicPath: '/',
        outputDir: 'dist',
        assetsDir: '',
        indexPath: 'index.html',
        filenameHashing: true,
        runtimeCompiler: false,
        transpileDependencies: [],
        productionSourceMap: true,
        parallel: true,
        pages: undefined,
        crossorigin: undefined,
        integrity: false,
        css: {},
        lintOnSave: 'default',
        devServer: {} } } }

在上面的api对象中我们可以看到,各命令对应的mode，即process.env.NODE_ENV

  modes:
      { serve: 'development',
        build: 'production',
        inspect: 'development' }

上面的api对应的属性projectOptions可在 node_modules > @vue > cli-service > lib> options.js 文件中查看到

exports.defaults = () => ({
  // project deployment base
  publicPath: '/',

  // where to output built files
  outputDir: 'dist',

  // where to put static assets (js/css/img/font/...)
  assetsDir: '',

  // filename for index.html (relative to outputDir)
  indexPath: 'index.html',

  // whether filename will contain hash part
  filenameHashing: true,

  // boolean, use full build?
  runtimeCompiler: false,

  // deps to transpile
  transpileDependencies: [
    /* string or regex */
  ],

  // sourceMap for production build?
  productionSourceMap: !process.env.VUE_CLI_TEST,

  // use thread-loader for babel & TS in production build
  // enabled by default if the machine has more than 1 cores
  parallel: hasMultipleCores(),

  // multi-page config
  pages: undefined,

  //