fix: Refactor GetModifiedSettingsContent for PS5 compatibility

Actions/CheckForUpdates/CheckForUpdates.HelperFunctions.ps1

@@ -727,7 +727,10 @@ function GetModifiedSettingsContent {
             $dstSettings | Add-Member -MemberType NoteProperty -Name "$schemaKey" -Value $schemaValue -Force
 
             # Make sure the $schema property is the first property in the object
-            $dstSettings = $dstSettings | Select-Object @{ Name = '$schema'; Expression = { $_.'$schema' } }, * -ExcludeProperty '$schema'
+            # PS5-safe: explicitly list properties instead of using wildcard to avoid literal '*' being added
+            $otherProperties = @($dstSettings.PSObject.Properties.Name | Where-Object { $_ -ne $schemaKey })
+            $selectProperties = @($schemaKey) + $otherProperties
+            $dstSettings = $dstSettings | Select-Object -Property $selectProperties
         }
     }
 

RELEASENOTES.md

@@ -4,6 +4,7 @@ Workspace compilation now finds altool both in the platform-specific subfolder (
 
 ### Issues
 
+- Issue 2285 - CheckForUpdates now handles settings file `$schema` reordering in a PowerShell 5-safe way to avoid writing invalid entries like `"*": null` to settings JSON files.
 - Fix "filename or extension is too long" error when validating settings on PS5.1 with large settings JSON
 - Retry downloading dependency artifacts from the current build up to 3 times (30 seconds between attempts) to tolerate transient network errors such as "Failed to GetSignedArtifactURL: Unable to make request: ETIMEDOUT"
 

Tests/CheckForUpdates.Action.Test.ps1

@@ -268,6 +268,21 @@ Describe "CheckForUpdates Action: CheckForUpdates.HelperFunctions.ps1" {
         $modifiedContent."srcSetting" | Should -Be "value1"
         $modifiedContent."`$schema" | Should -Be "someSchema"
     }
+
+    It 'GetModifiedSettingsContent does not create a literal * property when destination only contains $schema' {
+        # Repro for PS5 behavior where Select-Object with wildcard can emit "*": null
+        @{ "`$schema" = "sourceSchema"; "srcSetting" = "value1" } | ConvertTo-Json -Depth 10 | Out-File -FilePath $tmpSrcFile -Force
+        @{ "`$schema" = "destinationSchema" } | ConvertTo-Json -Depth 10 | Out-File -FilePath $tmpDstFile -Force
+
+        $modifiedContentJson = GetModifiedSettingsContent -srcSettingsFile $tmpSrcFile -dstSettingsFile $tmpDstFile
+        $modifiedContent = $modifiedContentJson | ConvertFrom-Json
+
+        $modifiedContent | Should -Not -BeNullOrEmpty
+        @($modifiedContent.PSObject.Properties.Name) | Should -Not -Contain '*'
+        $modifiedContentJson | Should -Not -Match '"\*"\s*:'
+        @($modifiedContent.PSObject.Properties.Name).Count | Should -Be 1
+        $modifiedContent."`$schema" | Should -Be "sourceSchema"
+    }
 }
 
 Describe "CheckForUpdates Action: ApplyWorkflowDefaultInputs Tests" {