Moved disk check into funcion to enable mocking

Author: PlagueHO

DSCResources/MSFT_xVirtualMemory/MSFT_xVirtualMemory.psm1

@@ -139,13 +139,7 @@ function Set-TargetResource
                 Set-AutoManagePaging -State Disable
             }
 
-            $driveInfo = [System.IO.DriveInfo] $Drive
-
-            if (-not $driveInfo.IsReady)
-            {
-                New-InvalidOperationException `
-                    -Message ($script:localizedData.DriveNotReadyError -f $driveInfo.Name)
-            }
+            $driveInfo = Get-DriveInfo -Drive $Drive
 
             $existingPageFileSetting = Get-PageFileSetting `
                 -Drive $($driveInfo.Name.Substring(0,2))
@@ -179,13 +173,7 @@ function Set-TargetResource
                 Set-AutoManagePaging -State Disable
             }
 
-            $driveInfo = [System.IO.DriveInfo] $Drive
-
-            if (-not $driveInfo.IsReady)
-            {
-                New-InvalidOperationException `
-                    -Message ($script:localizedData.DriveNotReadyError -f $driveInfo.Name)
-            }
+            $driveInfo = Get-DriveInfo -Drive $Drive
 
             $existingPageFileSetting = Get-PageFileSetting `
                 -Drive $($driveInfo.Name.Substring(0,2))
@@ -217,13 +205,7 @@ function Set-TargetResource
                 Set-AutoManagePaging -State Disable
             }
 
-            $driveInfo = [System.IO.DriveInfo] $Drive
-
-            if (-not $driveInfo.IsReady)
-            {
-                New-InvalidOperationException `
-                    -Message ($script:localizedData.DriveNotReadyError -f $driveInfo.Name)
-            }
+            $driveInfo = Get-DriveInfo -Drive $Drive
 
             $existingPageFileSetting = Get-PageFileSetting `
                 -Drive $($driveInfo.Name.Substring(0,2))
@@ -491,4 +473,36 @@ function New-PageFile
         }
 }
 
+<#
+    .SYNOPSIS
+        Gets the Drive info object for a specified
+        Drive. It will throw an exception if the drive
+        is invalid or does not exist.
+
+    .PARAMETER Drive
+        The letter of the drive to get the drive info
+        for.
+#>
+function Get-DriveInfo
+{
+    [CmdletBinding()]
+    [OutputType([System.IO.DriveInfo])]
+    param
+    (
+        [Parameter(Mandatory = $true)]
+        [System.String]
+        $Drive
+    )
+
+    $driveInfo = [System.IO.DriveInfo] $Drive
+
+    if (-not $driveInfo.IsReady)
+    {
+        New-InvalidOperationException `
+            -Message ($script:localizedData.DriveNotReadyError -f $driveInfo.Name)
+    }
+
+    return $driveInfo
+}
+
 Export-ModuleMember -Function *-TargetResource

Tests/Unit/MSFT_xVirtualMemory.Tests.ps1

@@ -41,11 +41,17 @@ try {
             )
         }
 
-        $testDrive = 'D:'
+        $testDrive = 'K:'
         $testInitialSize = 10
         $testMaximumSize = 20
         $testPageFileName = "$testDrive\pagefile.sys"
 
+        $mockGetDriveInfo = {
+            [PSObject] @{
+                Name = "$testDrive\"
+            }
+        }
+
         $mockAutomaticPagefileEnabled = {
             [PSObject] @{
                 AutomaticManagedPageFile = $true
@@ -251,6 +257,26 @@ try {
         }
 
         Describe 'MSFT_xVirtualMemory\Set-TargetResource' {
+            BeforeEach {
+                <#
+                    These mocks are to handle when disk drive
+                    used for testing does not exist.
+                #>
+                Mock `
+                    -CommandName Get-DriveInfo `
+                    -ParameterFilter { $Drive -eq $testDrive } `
+                    -MockWith $mockGetDriveInfo
+
+                Mock `
+                    -CommandName Join-Path `
+                    -ParameterFilter {
+                        $Path -eq "$testDrive\" -and `
+                        $ChildPath -eq 'pagefile.sys'
+                    } `
+                    -MockWith { "$testDrive\pagefile.sys"}
+
+            }
+
             Context 'When automatic managed page file should be enabled' {
                 Mock `
                     -CommandName Get-CimInstance `