Fix test failures in Npm and VSCode

resources/Microsoft.VSCode.Dsc/Microsoft.VSCode.Dsc.psm1

@@ -146,7 +146,6 @@ function Invoke-VSCode {
 
     $stdErrTempFile = Join-Path -Path ([System.IO.Path]::GetTempPath()) -ChildPath (New-Guid).Guid
     $stdOutTempFile = Join-Path -Path ([System.IO.Path]::GetTempPath()) -ChildPath (New-Guid).Guid
-    $invocationSuccess = $true
 
     $processParams = @{
         FilePath               = $VSCodeCLIPath
@@ -160,14 +159,14 @@ function Invoke-VSCode {
 
     $invocation = Start-Process @processParams
     $invocationErrors = Get-Content $stdErrTempFile -Raw -ErrorAction SilentlyContinue
-    $invocationErrors = $invocationErrors -replace '\n', '\n '
     $invocationOutput = Get-Content $stdOutTempFile -ErrorAction SilentlyContinue
     Remove-Item -Path $stdErrTempFile -ErrorAction Ignore
     Remove-Item -Path $stdOutTempFile -ErrorAction Ignore
 
-    if (![string]::IsNullOrWhiteSpace($invocationErrors)) { $invocationSuccess = $false }
-    if ($invocation.ExitCode) { $invocationSuccess = $false }
-    if (!$invocationSuccess) { throw [System.Configuration.ConfigurationException]::new("Executing '$VSCodeCLIPath $Command' failed. Command Output: '$invocationErrors'") }
+    if ($invocation.ExitCode -ne 0) {
+        $details = if ([string]::IsNullOrWhiteSpace($invocationErrors)) { $invocationOutput -join [System.Environment]::NewLine } else { $invocationErrors.Trim() }
+        throw [System.Configuration.ConfigurationException]::new("Executing '$VSCodeCLIPath $Command' failed with exit code $($invocation.ExitCode). Command Output: '$details'")
+    }
 
     return $invocationOutput
 }

resources/NpmDsc/NpmDsc.psm1

@@ -128,8 +128,11 @@ function GetNpmPath {
         } elseif (Test-Path $globalNpmCacheDir -ErrorAction SilentlyContinue) {
             return $globalNpmCacheDir
         } else {
-            $result = (Invoke-Npm -Command @('config', 'list', '--json') | ConvertFrom-Json -ErrorAction SilentlyContinue).cache
-            if (Test-Path $result -ErrorAction SilentlyContinue) {
+            # Call 'npm' directly rather than through Invoke-Npm: this is an error-reporting helper
+            # and Invoke-Npm's failure path calls back into GetNpmPath, which would recurse indefinitely.
+            $cacheRoot = (& npm config list --json --logs-max=0 2>$null | ConvertFrom-Json -ErrorAction SilentlyContinue).cache
+            $result = if ($cacheRoot) { Join-Path $cacheRoot '_logs' } else { $null }
+            if ($result -and (Test-Path $result -ErrorAction SilentlyContinue)) {
                 return $result
             } else {
                 return $null
@@ -428,15 +431,19 @@ class NpmPackage {
 
     [string] WhatIf() {
         if ($this.Ensure -eq [Ensure]::Present) {
-            $whatIfState = Install-NpmPackage -PackageName $this.Name -Global $this.Global -Arguments @('--dry-run')
-
             $out = @{
                 Name      = $this.Name
                 _metaData = @{
                     whatif = @()
                 }
             }
-            $out._metaData.whatif = $LASTEXITCODE -ne 0 ? (GetNpmWhatIfResponse) : ($whatIfState | Where-Object { $_.Trim() -ne '' }) # Removes empty lines from response
+
+            try {
+                $whatIfState = Install-NpmPackage -PackageName $this.Name -Global $this.Global -Arguments @('--dry-run')
+                $out._metaData.whatif = $whatIfState | Where-Object { $_.Trim() -ne '' } # Removes empty lines from response
+            } catch {
+                $out._metaData.whatif = GetNpmWhatIfResponse
+            }
         } else {
             # Uninstall does not have --dry-run param
             $out = @{}