说起源码，给我的第一印象是苦涩无趣，所以也一直是心里想着要读，但是一直未下手，刚好最近手上活儿少了点，又刚好在若川源码共读群里，就开始了

若川大佬的源码攻读已经有好多期了，我为什么从这篇vue3.2如何发布开始呢，大概是被这个标题吸引了吧，确实想知道平尤大到底怎么整的吧

当然我所写的是我觉得学到的必要的，详细的至[https://juejin.cn/post/6997943192851054606]查看更详细的调试及解读

vue3.2如何发布具体化今天要解读的是scripts/release.js文件

1. 环境及文件头部的依赖声明

1.1 环境

克隆项目，装包，修改指令

// 克隆项目
git clone https://github.com/lxchuan12/vue-next-analysis.git
git clone https://github.com/vuejs/vue-next.git

// 装包
cd vue-next
yarn install
// 修改指令
"scripts": {
  // --dry 参数是我加的，如果你是调试 代码也建议加
  // 不执行测试和编译 、不执行 推送git等操作
  // 也就是说空跑，只是打印，后文再详细讲述
  "release": "node scripts/release.js --dry",
  "preinstall": "node ./scripts/checkYarn.js",
}

2. 头部依赖及声明

2.1 依赖

 // vue-next/scripts/release.js
const args = require('minimist')(process.argv.slice(2))
// 文件模块
const fs = require('fs')
// 路径
const path = require('path')
// 控制台
const chalk = require('chalk')
const semver = require('semver')
const currentVersion = require('../package.json').version
const { prompt } = require('enquirer')

// 执行子进程命令   简单说 就是在终端命令行执行 命令
const execa = require('execa')

可以在 node_modules 找到对应安装的依赖，找到其README了解其大概用法解释和对应的github地址

2.1.1 minimist

var argv = require('minimist')(process.argv.slice(2));
console.log(argv);

其中的第一和第二个元素是Node可执行文件和被执行JavaScript文件的完全限定的文件系统路径，无论你是否这样输入他们。
执行

node test.js

process.argv前两个参数如下

{
  _: [
    '/Users/jryg/.nvm/versions/node/v14.18.2/bin/node',
    '/Users/jryg/Desktop/源码read/vue-next-analysis/vue-next/scripts/test.js'
  ]
}

minimist 作用就是解析之后的参数，如下：

$ node example/parse.js -a beep -b boop
{ _: [], a: 'beep', b: 'boop' }

$ node example/parse.js -x 3 -y 4 -n5 -abc --beep=boop foo bar baz
{ _: [ 'foo', 'bar', 'baz' ],
  x: 3,
  y: 4,
  n: 5,
  a: true,
  b: true,
  c: true,
  beep: 'boop' }

2.1.2 chalk 终端多色彩输出

在终端多色彩输出

2.1.3 semver 语义化版本

2.1.4 enquirer 交互式询问 CLI

2.1.5 execa 执行命令

const execa = require('execa');

(async () => {
    const {stdout} = await execa('echo', ['unicorns']);
    console.log(stdout);
    //=> 'unicorns'
})();

2.2 声明

2.2.1

// vue-next/scripts/release.js

// 对应 yarn run release --preid=beta
// beta
const preId =
  args.preid ||
  (semver.prerelease(currentVersion) && semver.prerelease(currentVersion)[0])
// 对应 yarn run release --dry
// true
const isDryRun = args.dry
// 对应 yarn run release --skipTests
// true 跳过测试
const skipTests = args.skipTests
// 对应 yarn run release --skipBuild 
// true
const skipBuild = args.skipBuild

// 读取 packages 文件夹，过滤掉 不是 .ts文件 结尾 并且不是 . 开头的文件夹
const packages = fs
  .readdirSync(path.resolve(__dirname, '../packages'))
  .filter(p => !p.endsWith('.ts') && !p.startsWith('.'))
// 跳过的包
const skippedPackages = []
// 版本递增
const versionIncrements = [
  'patch',
  'minor',
  'major',
  ...(preId ? ['prepatch', 'preminor', 'premajor', 'prerelease'] : [])
]

接着来

2.2.2

const inc = i => semver.inc(currentVersion, i, preId)
// 协助理解，也可查看semver学习  https://github.com/npm/node-semver#prerelease-identifie
// semver.inc('3.2.4', 'prerelease', 'beta')
// 3.2.5-beta.0

// 获取 node_modules/.bin/ 目录下的命令
// eg: bin('jest')   相当于在命令终端，项目根目录 运行 ./node_modules/.bin/jest 命令
const bin = name => path.resolve(__dirname, '../node_modules/.bin/' + name)

// 在终端跑真实命令      npm run build --release
const run = (bin, args, opts = {}) =>  execa(bin, args, { stdio: 'inherit', ...opts })
// 不跑真实命令，只是 console.log(); 打印 'yarn build --release'
const dryRun = (bin, args, opts = {}) =>   console.log(chalk.blue(`[dryrun] ${bin} ${args.join(' ')}`), opts)
// 是否真实跑命令
const runIfNotDry = isDryRun ? dryRun : run
// 获取packages下对应包的路径
const getPkgRoot = pkg => path.resolve(__dirname, '../packages/' + pkg)
// 控制台输出
const step = msg => console.log(chalk.cyan(msg))

3、接下来看主流程main函数

const chalk = require('chalk')
const step = msg => console.log(chalk.cyan(msg))
// 前面一堆依赖引入和函数定义等
async function main(){
  // 版本校验

  // run tests before release
  step('\nRunning tests...')
  // update all package versions and inter-dependencies
  step('\nUpdating cross dependencies...')
  // build all packages with types
  step('\nBuilding all packages...')

  // generate changelog
  step('\nCommitting changes...')

  // publish packages
  step('\nPublishing packages...')

  // push to GitHub
  step('\nPushing to GitHub...')
}

main().catch(err => {
  console.error(err)
})

去掉具体的一些方法实现后，可以看出main函数流程包括这么几步

3.1收看看一下test之前的一段代码

这段代码看起来很长，但功能很简单就是与用户交互选择对应的发布版本
结合图片一起观察

before-test.png

对应代码：

let targetVersion = args._[0]

  if (!targetVersion) {
    // no explicit version, offer suggestions
    const { release } = await prompt({
      type: 'select',
      name: 'release',
      message: 'Select release type',
      choices: versionIncrements.map(i => `${i} (${inc(i)})`).concat(['custom'])
    })

    if (release === 'custom') {
      targetVersion = (
        await prompt({
          type: 'input',
          name: 'version',
          message: 'Input custom version',
          initial: currentVersion
        })
      ).version
    } else {
      targetVersion = release.match(/\((.*)\)/)[1]
    }
  }

  if (!semver.valid(targetVersion)) {
    throw new Error(`invalid target version: ${targetVersion}`)
  }

  const { yes } = await prompt({
    type: 'confirm',
    name: 'yes',
    message: `Releasing v${targetVersion}. Confirm?`
  })

  if (!yes) {
    return
  }

3.2 step('\nRunning tests...')代码

jest执行测试

if (!skipTests && !isDryRun) {
    await run(bin('jest'), ['--clearCache'])
    await run('yarn', ['test', '--bail'])
  } else {
    console.log(`(skipped)`)
  }

3.3 step('\nUpdating cross dependencies...') 更新依赖

 updateVersions(targetVersion)
function updateVersions(version) {
  // 1. update root package.json
  updatePackage(path.resolve(__dirname, '..'), version)
  // 2. update all packages   
  packages.forEach(p => updatePackage(getPkgRoot(p), version))
}

function updatePackage(pkgRoot, version) {
  const pkgPath = path.resolve(pkgRoot, 'package.json')
  const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf-8'))
  pkg.version = version
  updateDeps(pkg, 'dependencies', version)
  updateDeps(pkg, 'peerDependencies', version)
  fs.writeFileSync(pkgPath, JSON.stringify(pkg, null, 2) + '\n')
}

function updateDeps(pkg, depType, version) {
  const deps = pkg[depType]
  if (!deps) return
  Object.keys(deps).forEach(dep => {
    if (
      dep === 'vue' ||
      (dep.startsWith('@vue') && packages.includes(dep.replace(/^@vue\//, '')))
    ) {
      console.log(
        chalk.yellow(`${pkg.name} -> ${depType} -> ${dep}@${version}`)
      )
      deps[dep] = version
    }
  })
}

3.4 打包，生成changelog

if (!skipBuild && !isDryRun) {
    await run('yarn', ['build', '--release'])
    // test generated dts files
    step('\nVerifying type declarations...')
    await run('yarn', ['test-dts-only'])
  } else {
    console.log(`(skipped)`)
  }

  // generate changelog
  await run(`yarn`, ['changelog'])

  const { stdout } = await run('git', ['diff'], { stdio: 'pipe' })
  if (stdout) {
    step('\nCommitting changes...')
    await runIfNotDry('git', ['add', '-A'])
    await runIfNotDry('git', ['commit', '-m', `release: v${targetVersion}`])
  } else {
    console.log('No changes to commit.')
  }

请看下图：

update-pkgs.png

3.5 step('\nPublishing packages...') 发布

for (const pkg of packages) {
    await publishPackage(pkg, targetVersion, runIfNotDry)
  }
async function publishPackage(pkgName, version, runIfNotDry) {
  if (skippedPackages.includes(pkgName)) {
    return
  }
  const pkgRoot = getPkgRoot(pkgName)
  const pkgPath = path.resolve(pkgRoot, 'package.json')
  const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf-8'))
  if (pkg.private) {
    return
  }

  // For now, all 3.x packages except "vue" can be published as
  // `latest`, whereas "vue" will be published under the "next" tag.
  let releaseTag = null
  if (args.tag) {
    releaseTag = args.tag
  } else if (version.includes('alpha')) {
    releaseTag = 'alpha'
  } else if (version.includes('beta')) {
    releaseTag = 'beta'
  } else if (version.includes('rc')) {
    releaseTag = 'rc'
  } else if (pkgName === 'vue') {
    // TODO remove when 3.x becomes default
    releaseTag = 'next'
  }

  // TODO use inferred release channel after official 3.0 release
  // const releaseTag = semver.prerelease(version)[0] || null

  step(`Publishing ${pkgName}...`)
  try {
    await runIfNotDry(
      'yarn',
      [
        'publish',
        '--new-version',
        version,
        ...(releaseTag ? ['--tag', releaseTag] : []),
        '--access',
        'public'
      ],
      {
        cwd: pkgRoot,
        stdio: 'pipe'
      }
    )
    console.log(chalk.green(`Successfully published ${pkgName}@${version}`))
  } catch (e) {
    if (e.stderr.match(/previously published/)) {
      console.log(chalk.red(`Skipping already published: ${pkgName}`))
    } else {
      throw e
    }
  }
}

执行命令后如图所示：

publish-pkgs.png

3.6 step('\nPushing to GitHub...') 发布

将对应代码推送至github

await runIfNotDry('git', ['tag', `v${targetVersion}`])
await runIfNotDry('git', ['push', 'origin', `refs/tags/v${targetVersion}`])
await runIfNotDry('git', ['push'])

至此，本次源码解读完毕！想要参加源码阅读的可留言，我带你直飞