feat: support built-in PM commands with -w flag

src/cli-flags.ts

@@ -73,7 +73,7 @@ export const FLAGS: FlagDef[] = [
 		long: '--workspace',
 		short: '-w',
 		key: 'workspace',
-		description: 'Run a package.json script across all workspaces',
+		description: 'Run a script or package manager command across all workspaces',
 		valueName: '<script>',
 		completionHint: 'none'
 	},

src/config/workspaces.test.ts

@@ -142,14 +142,41 @@ describe('resolveWorkspaceProcesses', () => {
 		expect(Object.keys(result)).toEqual(['web'])
 	})
 
-	test('error when no workspaces matched', () => {
+	test('error when no script and not a built-in command', () => {
 		const dir = setupMonorepo('no-match', {
 			rootPkg: { workspaces: ['packages/*'] },
 			workspaces: {
 				'packages/web': { name: 'web', scripts: { build: 'tsc' } }
 			}
 		})
-		expect(() => resolveWorkspaceProcesses('dev', dir)).toThrow('No workspaces have a "dev" script')
+		expect(() => resolveWorkspaceProcesses('xyznotacommand', dir)).toThrow('is not a built-in npm command')
+	})
+
+	test('built-in PM command runs in all workspaces', () => {
+		const dir = setupMonorepo('builtin-cmd', {
+			rootPkg: { workspaces: ['packages/*'] },
+			workspaces: {
+				'packages/web': { name: 'web', scripts: { dev: 'next dev' } },
+				'packages/api': { name: 'api', scripts: { dev: 'bun run api' } }
+			}
+		})
+		const result = resolveWorkspaceProcesses('install', dir)
+		expect(Object.keys(result).sort()).toEqual(['api', 'web'])
+		expect(result.web.command).toBe('npm install')
+	})
+
+	test('script takes priority over built-in command', () => {
+		const dir = setupMonorepo('script-priority', {
+			rootPkg: { workspaces: ['packages/*'] },
+			workspaces: {
+				'packages/web': { name: 'web', scripts: { test: 'vitest' } },
+				'packages/api': { name: 'api', scripts: { dev: 'bun run api' } }
+			}
+		})
+		// "test" is a built-in npm command, but web has a test script — so only web runs
+		const result = resolveWorkspaceProcesses('test', dir)
+		expect(Object.keys(result)).toEqual(['web'])
+		expect(result.web.command).toBe('npm run test')
 	})
 
 	test('PM detection reflected in command string', () => {

src/config/workspaces.ts

@@ -3,6 +3,18 @@ import { basename, resolve } from 'node:path'
 import type { NumuxConfig, NumuxProcessConfig, ResolvedProcessConfig } from '../types'
 import { detectPackageManager } from './expand-scripts'
 
+type PackageManager = 'npm' | 'yarn' | 'pnpm' | 'bun'
+
+/** Probe whether a command is a built-in package manager command by running
+ *  `<pm> <command> --help` and checking the exit code. */
+export function isBuiltinPmCommand(pm: PackageManager, command: string): boolean {
+	const result = Bun.spawnSync([pm, command, '--help'], {
+		stdout: 'ignore',
+		stderr: 'ignore'
+	})
+	return result.exitCode === 0
+}
+
 export interface WorkspaceInfo {
 	dir: string
 	/** Scope-stripped pkg.name or dir basename */
@@ -168,24 +180,39 @@ export function resolveWorkspaceProcesses(script: string, cwd: string): Record<s
 
 	for (const ws of workspaces) {
 		if (!ws.scripts[script]) continue
+		addWorkspace(processes, usedNames, ws, `${pm} run ${script}`)
+	}
 
-		let name = ws.name
-		if (usedNames.has(name)) {
-			let suffix = 1
-			while (usedNames.has(`${name}-${suffix}`)) suffix++
-			name = `${name}-${suffix}`
+	// If no workspace has the script, fall back to a built-in PM command
+	// (e.g. `install`, `outdated`) run across every workspace. Such commands
+	// exit on completion, so persistence is auto-detected (no readyPattern).
+	if (Object.keys(processes).length === 0) {
+		if (!isBuiltinPmCommand(pm, script)) {
+			throw new Error(`No workspaces have a "${script}" script and "${script}" is not a built-in ${pm} command`)
 		}
-		usedNames.add(name)
 
-		processes[name] = {
-			command: `${pm} run ${script}`,
-			cwd: ws.dir
+		for (const ws of workspaces) {
+			addWorkspace(processes, usedNames, ws, `${pm} ${script}`)
 		}
 	}
 
-	if (Object.keys(processes).length === 0) {
-		throw new Error(`No workspaces have a "${script}" script`)
+	return processes
+}
+
+function addWorkspace(
+	processes: Record<string, ResolvedProcessConfig>,
+	usedNames: Set<string>,
+	ws: WorkspaceInfo,
+	command: string
+): void {
+	// Deduplicate names
+	let name = ws.name
+	if (usedNames.has(name)) {
+		let suffix = 1
+		while (usedNames.has(`${name}-${suffix}`)) suffix++
+		name = `${name}-${suffix}`
 	}
+	usedNames.add(name)
 
-	return processes
+	processes[name] = { command, cwd: ws.dir }
 }