feat: xpm set-config

Author: Yonom

README.md

@@ -1,13 +1,18 @@
 # xpm - Universal Package Manager Wrapper
 
-`xpm` is built for those who work across multiple projects with different package managers. You can use `xpm` instead of `npm`/`yarn`/`pnpm`/`bun`. `xpm` invokes the right package manager for you. Additonally, it installs package dependencies if you forgot to do it.
+Working across multiple projects with different package managers? 
+
+You can use `xpm` instead of `npm`/`yarn`/`pnpm`/`bun`.
+
+Think of `xpm` as your universal translator for package managers. When you run `xpm`, it figures out which package manager your project uses, ensures your dependencies are up-to-date, and runs the appropriate command. It's like having muscle memory that works everywhere.
 
 For example, when you run `xpm dev` in a project:
 
-- xpm detects the package manager
-- auto-installs dependencies if necessary (compares lockfile hash)
+- `xpm` detects the package manager
+- it auto-installs dependencies if necessary (compares lockfile hash)
 - runs `npm run dev` / `yarn dev` / `pnpm dev` / `bun dev`
 
+
 ## Install
 
 ```bash
@@ -33,6 +38,20 @@ xpm dev           # Run a script
 xpx prettier      # Download and run from the registry
 ```
 
+## Configuration
+
+Set the default package manager for new projects:
+
+```bash
+xpm set-config default-package-manager pnpm
+```
+
+The default is used when no lockfile or package.json `packageManager` field is found.
+
+You can also set it via environment variable:
+```bash
+export XPM_DEFAULT_PM=bun
+```
 
 ## License
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@assistant-ui/xpm",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "Universal package manager wrapper that automatically detects and uses the right package manager",
   "main": "dist/index.js",
   "bin": {

src/config.ts

@@ -0,0 +1,55 @@
+import { readFileSync, existsSync, writeFileSync, mkdirSync } from 'fs';
+import { homedir } from 'os';
+import { join, dirname } from 'path';
+import { PackageManager } from './package-manager-config';
+
+const CONFIG_PATH = join(homedir(), '.xpmrc');
+
+export function getDefaultPackageManager(): PackageManager {
+  // 1. Check environment variable
+  const envPM = process.env.XPM_DEFAULT_PM;
+  if (envPM && isValidPackageManager(envPM)) {
+    return envPM as PackageManager;
+  }
+
+  // 2. Check config file in home directory
+  if (existsSync(CONFIG_PATH)) {
+    try {
+      const config = JSON.parse(readFileSync(CONFIG_PATH, 'utf-8'));
+      if (config.defaultPackageManager && isValidPackageManager(config.defaultPackageManager)) {
+        return config.defaultPackageManager;
+      }
+    } catch {}
+  }
+
+  // 3. Fall back to npm
+  return 'npm';
+}
+
+export function setDefaultPackageManager(pm: string): void {
+  if (!isValidPackageManager(pm)) {
+    throw new Error(`Invalid package manager: ${pm}. Must be one of: npm, yarn, pnpm, bun`);
+  }
+  
+  let config: any = {};
+  if (existsSync(CONFIG_PATH)) {
+    try {
+      config = JSON.parse(readFileSync(CONFIG_PATH, 'utf-8'));
+    } catch {}
+  }
+  
+  config.defaultPackageManager = pm;
+  
+  // Ensure directory exists
+  const dir = dirname(CONFIG_PATH);
+  if (!existsSync(dir)) {
+    mkdirSync(dir, { recursive: true });
+  }
+  
+  writeFileSync(CONFIG_PATH, JSON.stringify(config, null, 2));
+  console.log(`Default package manager set to: ${pm}`);
+}
+
+function isValidPackageManager(pm: string): boolean {
+  return ['npm', 'yarn', 'pnpm', 'bun'].includes(pm);
+}

src/detector.ts

@@ -1,6 +1,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import { PackageManager, PACKAGE_MANAGERS, SUPPORTED_PACKAGE_MANAGERS } from './package-manager-config';
+import { getDefaultPackageManager } from './config';
 
 export interface DetectionResult {
   packageManager: PackageManager;
@@ -47,7 +48,7 @@ export function detectPackageManager(startDir = process.cwd()): DetectionResult
   const isWorkspace = lockfileDir !== null && lockfileDir !== packageJsonDir;
 
   // Try to read package.json for corepack config
-  let detectedPM: PackageManager = 'npm';
+  let detectedPM: PackageManager | null = null;
   try {
     const packageJson = JSON.parse(fs.readFileSync(path.join(detectionRoot, 'package.json'), 'utf-8'));
     const pmField = packageJson.packageManager ?? packageJson.devEngines?.packageManager?.name;
@@ -60,7 +61,7 @@ export function detectPackageManager(startDir = process.cwd()): DetectionResult
   } catch {}
 
   // Check for lockfiles if no corepack config
-  if (detectedPM === 'npm') {
+  if (!detectedPM) {
     for (const manager of ['bun', 'pnpm', 'yarn', 'npm'] as PackageManager[]) {
       if (fs.existsSync(path.join(detectionRoot, PACKAGE_MANAGERS[manager].lockfile))) {
         detectedPM = manager;
@@ -69,6 +70,11 @@ export function detectPackageManager(startDir = process.cwd()): DetectionResult
     }
   }
 
+  // Fall back to configured default
+  if (!detectedPM) {
+    detectedPM = getDefaultPackageManager();
+  }
+  
   return {
     packageManager: detectedPM,
     projectRoot: packageJsonDir,

src/xpm.ts

@@ -2,6 +2,7 @@ import { spawn } from 'child_process';
 import { detectPackageManager, shouldRunAtWorkspaceRoot } from './detector';
 import { synchronizeDependencies } from './dependency-synchronizer';
 import { mapCommand } from './command-mapper';
+import { setDefaultPackageManager } from './config';
 
 const skipInstallCommands = ['install', 'i', 'add', 'remove', 'uninstall', 'update', 'upgrade'];
 
@@ -53,19 +54,39 @@ Commands:
   install/i/add [pkg]  Install package(s)
   remove/rm/uninstall  Remove package
   upgrade              Update packages
+  set-config           Set configuration
   [script]             Run package.json script
 
 Flags: --dry-run, --version/-v, --help/-h
 
+Config:
+  xpm set-config default-package-manager <npm|yarn|pnpm|bun>
+
 Detects: npm/yarn/pnpm/bun`);
   }
 
   run(): void {
     this.parseFlags();
 
+    // Handle set-config command
+    const [command, ...args] = this.args;
+    if (command === 'set-config') {
+      if (args[0] === 'default-package-manager' && args[1]) {
+        try {
+          setDefaultPackageManager(args[1]);
+          process.exit(0);
+        } catch (error) {
+          console.error(error instanceof Error ? error.message : error);
+          process.exit(1);
+        }
+      } else {
+        console.error('Usage: xpm set-config default-package-manager <npm|yarn|pnpm|bun>');
+        process.exit(1);
+      }
+    }
+
     try {
       const { packageManager, projectRoot, isWorkspace, workspaceRoot } = detectPackageManager();
-      const [command, ...args] = this.args;
 
       // Auto-sync dependencies unless it's an install-like command or no command
       if (command && !skipInstallCommands.includes(command)) {