vue create [project-name]做了什么？

先看一下vue create生成的log

Vue CLI v3.4.1
? Please pick a preset: default (babel, eslint)

Vue CLI v3.4.1
✨  Creating project in /Users/wangweiren/Documents/project/vue-hello.
?  Initializing git repository...
⚙  Installing CLI plugins. This might take a while...

// https://www.npmjs.com/package/fsevents
// 可以监听某个目录
> fsevents@1.2.7 install /Users/wangweiren/Documents/project/vue-hello/node_modules/fsevents
> node install

[fsevents] Success: "/Users/wangweiren/Documents/project/vue-hello/node_modules/fsevents/lib/binding/Release/node-v64-darwin-x64/fse.node" is ins
talled via remote

> yorkie@2.0.0 install /Users/wangweiren/Documents/project/vue-hello/node_modules/yorkie
> node bin/install.js

setting up Git hooks
done

added 1181 packages from 657 contributors and audited 23486 packages in 57.302s
found 0 vulnerabilities

?  Invoking generators...
?  Installing additional dependencies...

added 37 packages from 28 contributors, updated 2 packages, moved 9 packages and audited 23774 packages in 28.952s
found 0 vulnerabilities

⚓  Running completion hooks...

?  Generating README.md...

?  Successfully created project vue-hello.
?  Get started with the following commands:

$ cd vue-hello
$ npm run serve

vue 命令的node代码

#!/usr/bin/env node

program
  .command('create <app-name>')
  .description('create a new project powered by vue-cli-service')
  .option('-p, --preset <presetName>', 'Skip prompts and use saved or remote preset')
  .option('-d, --default', 'Skip prompts and use default preset')
  .option('-i, --inlinePreset <json>', 'Skip prompts and use inline JSON string as preset')
  .option('-m, --packageManager <command>', 'Use specified npm client when installing dependencies')
  .option('-r, --registry <url>', 'Use specified npm registry when installing dependencies (only for npm)')
  .option('-g, --git [message]', 'Force git initialization with initial commit message')
  .option('-n, --no-git', 'Skip git initialization')
  .option('-f, --force', 'Overwrite target directory if it exists')
  .option('-c, --clone', 'Use git clone when fetching remote preset')
  .option('-x, --proxy', 'Use specified proxy when creating project')
  .option('-b, --bare', 'Scaffold project without beginner instructions')
  .action((name, cmd) => {
    const options = cleanArgs(cmd)

    if (minimist(process.argv.slice(3))._.length > 1) {
      console.log(chalk.yellow('\n Info: You provided more than one argument. The first one will be used as the app\'s name, the rest are ignored.'))
    }
    // --git makes commander to default git to true
    if (process.argv.includes('-g') || process.argv.includes('--git')) {
      options.forceGit = true
    }
    require('../lib/create')(name, options)
  })

发现用了当前目录上一级/lib/create这个文件，我们接着看一下，发现这个文件做了一系列的判断之后~，然后执行了

const creator = new Creator(name, targetDir, getPromptModules());
await creator.create(options)

create方法

async create (cliOptions = {}, preset = null) {
    const isTestOrDebug = process.env.VUE_CLI_TEST || process.env.VUE_CLI_DEBUG
    const { run, name, context, createCompleteCbs } = this

    if (!preset) {
      if (cliOptions.preset) {
        // vue create foo --preset bar
        preset = await this.resolvePreset(cliOptions.preset, cliOptions.clone)
      } else if (cliOptions.default) {
        // vue create foo --default
        preset = defaults.presets.default
      } else if (cliOptions.inlinePreset) {
        // vue create foo --inlinePreset {...}
        try {
          preset = JSON.parse(cliOptions.inlinePreset)
        } catch (e) {
          error(`CLI inline preset is not valid JSON: ${cliOptions.inlinePreset}`)
          exit(1)
        }
      } else {
        preset = await this.promptAndResolvePreset()
      }
    }

    // clone before mutating
    preset = cloneDeep(preset)
    // inject core service
    preset.plugins['@vue/cli-service'] = Object.assign({
      projectName: name
    }, preset, {
      bare: cliOptions.bare
    })

    const packageManager = (
      cliOptions.packageManager ||
      loadOptions().packageManager ||
      (hasYarn() ? 'yarn' : 'npm')
    )

    await clearConsole()
    logWithSpinner(`✨`, `Creating project in ${chalk.yellow(context)}.`)
    this.emit('creation', { event: 'creating' })

    // get latest CLI version
    const { latest } = await getVersions()
    const latestMinor = `${semver.major(latest)}.${semver.minor(latest)}.0`
    // generate package.json with plugin dependencies
    const pkg = {
      name,
      version: '0.1.0',
      private: true,
      devDependencies: {}
    }
    const deps = Object.keys(preset.plugins)
    deps.forEach(dep => {
      if (preset.plugins[dep]._isPreset) {
        return
      }

      // Note: the default creator includes no more than `@vue/cli-*` & `@vue/babel-preset-env`,
      // so it is fine to only test `@vue` prefix.
      // Other `@vue/*` packages' version may not be in sync with the cli itself.
      pkg.devDependencies[dep] = (
        preset.plugins[dep].version ||
        ((/^@vue/.test(dep)) ? `^${latestMinor}` : `latest`)
      )
    })
    // write package.json
    await writeFileTree(context, {
      'package.json': JSON.stringify(pkg, null, 2)
    })

    // intilaize git repository before installing deps
    // so that vue-cli-service can setup git hooks.
    const shouldInitGit = this.shouldInitGit(cliOptions)
    if (shouldInitGit) {
      logWithSpinner(`?`, `Initializing git repository...`)
      this.emit('creation', { event: 'git-init' })
      await run('git init')
    }

    // install plugins
    stopSpinner()
    log(`⚙  Installing CLI plugins. This might take a while...`)
    log()
    this.emit('creation', { event: 'plugins-install' })
    if (isTestOrDebug) {
      // in development, avoid installation process
      await require('./util/setupDevProject')(context)
    } else {
      await installDeps(context, packageManager, cliOptions.registry)
    }

    // run generator
    log(`?  Invoking generators...`)
    this.emit('creation', { event: 'invoking-generators' })
    const plugins = await this.resolvePlugins(preset.plugins)
    const generator = new Generator(context, {
      pkg,
      plugins,
      completeCbs: createCompleteCbs
    })
    await generator.generate({
      extractConfigFiles: preset.useConfigFiles
    })

    // install additional deps (injected by generators)
    log(`?  Installing additional dependencies...`)
    this.emit('creation', { event: 'deps-install' })
    log()
    if (!isTestOrDebug) {
      await installDeps(context, packageManager, cliOptions.registry)
    }

    // run complete cbs if any (injected by generators)
    logWithSpinner('⚓', `Running completion hooks...`)
    this.emit('creation', { event: 'completion-hooks' })
    for (const cb of createCompleteCbs) {
      await cb()
    }

    // generate README.md
    stopSpinner()
    log()
    logWithSpinner('?', 'Generating README.md...')
    await writeFileTree(context, {
      'README.md': generateReadme(generator.pkg, packageManager)
    })

    // commit initial state
    let gitCommitFailed = false
    if (shouldInitGit) {
      await run('git add -A')
      if (isTestOrDebug) {
        await run('git', ['config', 'user.name', 'test'])
        await run('git', ['config', 'user.email', '[e-mail]'])
      }
      const msg = typeof cliOptions.git === 'string' ? cliOptions.git : 'init'
      try {
        await run('git', ['commit', '-m', msg])
      } catch (e) {
        gitCommitFailed = true
      }
    }

    // log instructions
    stopSpinner()
    log()
    log(`?  Successfully created project ${chalk.yellow(name)}.`)
    log(
      `?  Get started with the following commands:\n\n` +
      (this.context === process.cwd() ? `` : chalk.cyan(` ${chalk.gray('$')} cd ${name}\n`)) +
      chalk.cyan(` ${chalk.gray('$')} ${packageManager === 'yarn' ? 'yarn serve' : 'npm run serve'}`)
    )
    log()
    this.emit('creation', { event: 'done' })

    if (gitCommitFailed) {
      warn(
        `Skipped git commit due to missing username and email in git config.\n` +
        `You will need to perform the initial commit yourself.\n`
      )
    }

    generator.printExitLogs()
  }

欢迎交流~