Fix Windows spawn issues by enabling shell for .cmd files

Author: jdalton

src/agent.ts

@@ -25,6 +25,7 @@
 
 import { CI } from '#env/ci'
 
+import { WIN32 } from '#constants/platform'
 import { execBin } from './bin'
 import { isDebug } from './debug'
 import { findUpSync } from './fs'
@@ -128,6 +129,8 @@ export function execNpm(args: string[], options?: SpawnOptions | undefined) {
     ],
     {
       __proto__: null,
+      // On Windows, npm is a .cmd file that requires shell to execute.
+      shell: WIN32,
       ...options,
     } as SpawnOptions,
   )

src/bin.ts

@@ -8,6 +8,7 @@ import { HOME } from '#env/home'
 import { LOCALAPPDATA } from '#env/localappdata'
 import { XDG_DATA_HOME } from '#env/xdg-data-home'
 
+import { WIN32 } from '#constants/platform'
 import { readJsonSync } from './fs'
 import { getOwn } from './objects'
 import { isPath, normalizePath } from './path'
@@ -79,7 +80,11 @@ export async function execBin(
   const binCommand = Array.isArray(resolvedPath)
     ? resolvedPath[0]!
     : resolvedPath
-  return await spawn(binCommand, args ?? [], options)
+  // On Windows, binaries are often .cmd files that require shell to execute.
+  return await spawn(binCommand, args ?? [], {
+    shell: WIN32,
+    ...options,
+  })
 }
 
 /**
@@ -248,7 +253,6 @@ export function findRealNpm(): string {
  * Find the real pnpm executable, bypassing any aliases and shadow bins.
  */
 export function findRealPnpm(): string {
-  const WIN32 = require('../constants/platform').WIN32
   const path = getPath()
 
   // Try common pnpm locations.
@@ -381,7 +385,6 @@ export function resolveBinPathSync(binPath: string): string {
       return voltaBinPath
     }
   }
-  const WIN32 = require('../constants/platform').WIN32
   if (WIN32) {
     const hasKnownExt =
       extLowered === '' ||

src/git.ts

@@ -1,5 +1,6 @@
 import path from 'node:path'
 
+import { WIN32 } from '#constants/platform'
 import { getGlobMatcher } from './globs'
 import { normalizePath } from './path'
 import { spawn, spawnSync } from './spawn'
@@ -231,7 +232,7 @@ function getGitDiffSpawnArgs(cwd?: string | undefined): GitDiffSpawnArgs {
       ['status', '--porcelain'],
       {
         cwd: resolvedCwd,
-        shell: process.platform === 'win32',
+        shell: WIN32,
       },
     ],
     unstaged: [
@@ -246,7 +247,7 @@ function getGitDiffSpawnArgs(cwd?: string | undefined): GitDiffSpawnArgs {
       ['diff', '--cached', '--name-only'],
       {
         cwd: resolvedCwd,
-        shell: process.platform === 'win32',
+        shell: WIN32,
       },
     ],
   }

src/temporary-executor.ts

@@ -3,6 +3,7 @@
  * Identifies and handles temporary execution contexts such as npx, pnpm dlx, and yarn dlx.
  */
 
+import { WIN32 } from '#constants/platform'
 import { normalizePath } from './path'
 
 /**
@@ -46,7 +47,7 @@ export function isRunningInTemporaryExecutor(cwd = process.cwd()): boolean {
   ]
 
   // Yarn on Windows uses AppData/Local/Temp/xfs- pattern.
-  if (process.platform === 'win32') {
+  if (WIN32) {
     tempPatterns.push('AppData/Local/Temp/xfs-')
   }