TL;DR

Expose package manager detection and download functionality through the CLI binding API.

What changed?

• Added two new public functions to the CLI binding API:
  • detectWorkspace: Detects the workspace root, package manager type, version, and whether it's a monorepo
  • downloadPackageManager: Downloads a specified package manager version
• Refactored the package manager download logic in vite_install to make it more modular and reusable
• Added TypeScript type definitions and JSDoc documentation for the new functions
• Created tests for the new functionality with fixtures for different project types

How to test?

1. Run the new tests:

   pnpm test packages/cli/src/__tests__/detectWorkspace.spec.ts
   pnpm test packages/cli/src/__tests__/downloadPackageManager.spec.ts
   

2. Try using the new API in a project:

   import { detectWorkspace, downloadPackageManager } from '@vitejs/cli';
   
   // Detect workspace and package manager
   const workspace = await detectWorkspace(process.cwd());
   console.log(workspace);
   
   // Download a package manager
   const result = await downloadPackageManager({
     name: 'pnpm',
     version: 'latest'
   });
   console.log(result);

Why make this change?

This change enables external tools and plugins to leverage Vite's package manager detection and download capabilities. By exposing these functions through the CLI binding API, other tools can reliably determine the project structure and ensure the correct package manager is available without reimplementing this logic.