xGroupResource: Force array type for members (#773)

Author: webalexeu

CHANGELOG.md

@@ -5,6 +5,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- xGroup
+  - Fixed a bug where the get resource would fail if group members is empty [Issue #772](https://github.com/dsccommunity/xPSDesiredStateConfiguration/issues/772)
+
 ## [9.2.0] - 2024-10-15
 
 ### Fixed

source/DSCResources/DSC_xGroupResource/DSC_xGroupResource.psm1

@@ -383,13 +383,8 @@ function Get-TargetResourceOnFullSKU
             $null = $disposables.Add($group)
 
             # The group was found. Find the group members.
-            $members = Get-MembersOnFullSKU -Group $group -PrincipalContextCache $principalContextCache `
-                -Credential $Credential -Disposables $disposables
-
-            if ($members -is [System.String])
-            {
-                $members = @($members)
-            }
+            [System.String[]] $members = @(Get-MembersOnFullSKU -Group $group -PrincipalContextCache $principalContextCache `
+                -Credential $Credential -Disposables $disposables)
 
             return @{
                 GroupName = $group.Name
@@ -459,12 +454,7 @@ function Get-TargetResourceOnNanoServer
     }
 
     # The group was found. Find the group members.
-    $members = Get-MembersOnNanoServer -Group $group
-
-    if ($members -is [System.String])
-    {
-        $members = @($members)
-    }
+    [System.String[]] $members = @(Get-MembersOnNanoServer -Group $group)
 
     return @{
         GroupName = $group.Name

tests/Unit/DSC_xGroupResource.Tests.ps1

@@ -944,7 +944,8 @@ try
                         $getTargetResourceResult.GroupName | Should -Be $script:testGroupName
                         $getTargetResourceResult.Ensure | Should -Be 'Present'
                         $getTargetResourceResult.Description | Should -Be $script:testGroupDescription
-                        $getTargetResourceResult.Members | Should -Be $null
+                        $getTargetResourceResult.Members -is [System.String[]] | Should -BeTrue
+                        $getTargetResourceResult.Members.Count | Should -Be 0
                     }
 
                     It 'Should return correct hashtable values when Get-Group returns a valid, existing group with a single member' {
@@ -965,7 +966,8 @@ try
                         $getTargetResourceResult.Ensure | Should -Be 'Present'
                         $getTargetResourceResult.Description | Should -Be $script:testGroupDescription
                         $getTargetResourceResult.Members | Should -Be $testMembersSingle
-                        $getTargetResourceResult.Members -is [System.Object[]] | Should -BeTrue
+                        $getTargetResourceResult.Members -is [System.String[]] | Should -BeTrue
+                        $getTargetResourceResult.Members.Count | Should -Be 1
                     }
 
                     It 'Should return correct hashtable values when Get-Group returns a valid, existing group with multiple members' {
@@ -986,6 +988,8 @@ try
                         $getTargetResourceResult.Ensure | Should -Be 'Present'
                         $getTargetResourceResult.Description | Should -Be $script:testGroupDescription
                         $getTargetResourceResult.Members | Should -Be $testMembersMultiple
+                        $getTargetResourceResult.Members -is [System.String[]] | Should -BeTrue
+                        $getTargetResourceResult.Members.Count | Should -BeGreaterThan 1
                     }
                 }