详解PNPM Monorepo依赖项管理功能模拟实现

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const fs = require('fs');
const path = require('path');
const packageJson = JSON.parse(fs.readFileSync('./package.json'));
const packages = packageJson.workspaces.packages;

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if (!fs.existsSync('node_modules')) {
  fs.mkdirSync('node_modules');
}
// 遍历所有子项目
packages.forEach((pkg) => {
  // 获取子项目的 package.json 文件路径和 node_modules 路径
  const pkgPath = path.join(pkg, 'package.json');
  const nodeModulesPath = path.join(pkg, 'node_modules');
  // 如果子项目的 node_modules 目录不存在，则创建一个软链接，指向根目录下的 node_modules 目录
  if (!fs.existsSync(nodeModulesPath)) {
    fs.symlinkSync(path.resolve('node_modules'), nodeModulesPath, 'dir');
  }
});

// 遍历所有子项目
packages.forEach((pkg) => {
  // 安装子项目的依赖项
  // 读取子项目的 package.json 文件，获取依赖项列表
  const packageJson = JSON.parse(fs.readFileSync(pkgPath));
  const dependencies = packageJson.dependencies || {};
  // 遍历依赖项列表，安装依赖项，并在子项目的 node_modules 目录中创建硬链接
  for (const dep in dependencies) {
    const version = dependencies[dep];
    const depPath = path.join(nodeModulesPath, dep);
    const depVersionPath = path.join(depPath, version);
    const globalDepVersionPath = path.join('node_modules', dep, version);
    // 检查是否已经安装过该版本的依赖项
    if (!fs.existsSync(depVersionPath)) {
      // 如果未安装，则使用 spawnSync 函数执行 npm install 命令安装依赖项
      console.log(`Installing ${dep}@${version}...`);
      spawnSync('npm', ['install', `${dep}@${version}`], { cwd: pkg, stdio: 'inherit' });
      // 创建硬链接，将子项目的依赖项与根目录下的依赖项进行链接
      if (fs.existsSync(globalDepVersionPath)) {
        fs.linkSync(globalDepVersionPath, depVersionPath);
      } else {
        // 如果根目录下没有该依赖项，则创建一个软链接，指向根目录下的依赖项
        fs.mkdirSync(depPath);
        fs.symlinkSync(globalDepVersionPath, depVersionPath, 'dir');
      }
    }
  }
});

const fs = require('fs');
const path = require('path');
const { spawnSync } = require('child_process');
function installDependencies() {
  const packageJson = JSON.parse(fs.readFileSync('./package.json'));
  const packages = packageJson.workspaces.packages;
  if (!fs.existsSync('node_modules')) {
    fs.mkdirSync('node_modules');
  }
  packages.forEach((pkg) => {
    const pkgPath = path.join(pkg, 'package.json');
    const nodeModulesPath = path.join(pkg, 'node_modules');
    if (!fs.existsSync(nodeModulesPath)) {
      fs.symlinkSync(path.resolve('node_modules'), nodeModulesPath, 'dir');
    }
    const packageJson = JSON.parse(fs.readFileSync(pkgPath));
    const dependencies = packageJson.dependencies || {};
    for (const dep in dependencies) {
      const version = dependencies[dep];
      const depPath = path.join(nodeModulesPath, dep);
      const depVersionPath = path.join(depPath, version);
      const globalDepVersionPath = path.join('node_modules', dep, version);
      if (!fs.existsSync(depVersionPath)) {
        console.log(`Installing ${dep}@${version}...`);
        spawnSync('npm', ['install', `${dep}@${version}`], { cwd: pkg, stdio: 'inherit' });
        if (fs.existsSync(globalDepVersionPath)) {
          fs.linkSync(globalDepVersionPath, depVersionPath);
        } else {
          fs.mkdirSync(depPath);
          fs.symlinkSync(globalDepVersionPath, depVersionPath, 'dir');
        }
      }
    }
  });
  console.log('All dependencies installed!');
}
installDependencies();