fix(harness): start child processes without NoDefaultCurrentDirectoryInExePath

CHANGELOG.md

@@ -11,7 +11,13 @@ release notes.
 
 ## [Unreleased]
 
-Nothing yet.
+### Fixed
+
+- A Win32 install or uninstall command named as a bare batch file (`install.cmd`) failed with
+  "'install.cmd' is not recognized" from `Invoke-IntuneWin32AppTest` on a machine where
+  `NoDefaultCurrentDirectoryInExePath` is set in the caller's environment, a per-user shell
+  setting that stops `cmd.exe` looking in its working folder. The agent's `cmd.exe` runs without
+  the caller's profile, so the harness now starts its child processes without the variable.
 
 ## [0.29.0] - 2026-10-07
 

Private/Invoke-IslProcess.ps1

@@ -85,6 +85,10 @@
             if ($desktopModulePath) { $startInfo.Environment['PSModulePath'] = $desktopModulePath }
             else { $null = $startInfo.Environment.Remove('PSModulePath') }
         }
+        # With NoDefaultCurrentDirectoryInExePath set in the caller's own environment, cmd.exe does
+        # not look in its working folder, and a bare 'install.cmd' fails with "not recognized". The
+        # agent's cmd.exe runs without the caller's profile, so the child runs without the setting
+        $null = $startInfo.Environment.Remove('NoDefaultCurrentDirectoryInExePath')
 
         $process = [System.Diagnostics.Process]::new()
         $process.StartInfo = $startInfo

Tests/Unit/Private/Invoke-IslProcess.Tests.ps1

@@ -47,6 +47,26 @@ Describe 'Invoke-IslProcess' -Tag 'Unit', 'Private' {
             $result.StdOut.Trim() | Should-Be $TestDrive
         }
 
+        It 'lets cmd.exe find a batch file in the working folder whatever the caller''s own shell setting' {
+            # NoDefaultCurrentDirectoryInExePath in the caller's environment stops cmd.exe looking in
+            # the working folder; the agent's cmd.exe has no such setting, so the child must not either
+            Set-Content -Path (Join-Path $TestDrive 'install.cmd') -Value '@echo ran' -Encoding ascii
+            $saved = $env:NoDefaultCurrentDirectoryInExePath
+            $env:NoDefaultCurrentDirectoryInExePath = '1'
+            try {
+                $result = Invoke-Process @{
+                    FilePath = $script:Cmd; Arguments = '/C "install.cmd"'
+                    WorkingDirectory = $TestDrive; WorkFolder = $TestDrive
+                }
+            }
+            finally {
+                $env:NoDefaultCurrentDirectoryInExePath = $saved
+            }
+            $result.ExitCode | Should-Be 0
+            $result.StdOut.Trim() | Should-Be 'ran'
+            $result.StdErr.Trim() | Should-Be ''
+        }
+
         It 'closes stdin so a read returns instead of waiting' {
             $result = Invoke-Process @{
                 FilePath = $script:Cmd; Arguments = '/C set /p answer=name? & echo [%answer%]'