Auto-mounted file system drives correctly created when mounted inside a module (#3034)

Fixes #2442

src/System.Management.Automation/engine/SessionStateDriveAPIs.cs

@@ -508,12 +508,13 @@ namespace System.Management.Automation
 
             if (result == null && automount)
             {
-                result = AutomountBuiltInDrive(name);
-            }
-
-            if (result == null && this == ExecutionContext.TopLevelSessionState)
-            {
-                result = AutomountFileSystemDrive(name);
+                // first try to automount as a file system drive
+                result = AutomountFileSystemDrive(name);
+                // if it didn't work, then try automounting as a BuiltIn drive (e.g. "Cert"/"Certificate"/"WSMan")
+                if (result == null)
+                {
+                    result = AutomountBuiltInDrive(name); // internally this calls GetDrive(name, false)
+                }
             }
 
             if (result == null)

test/powershell/Provider/AutomountSubstDrive.ps1

@@ -0,0 +1,38 @@
+# Precondition: start from fresh PS session, do not have the media mounted
+param([switch]$useModule, [string]$FullPath)
+
+$global:CoreScriptPath = Join-Path $PSScriptRoot 'AutomountSubstDriveCore.ps1'
+
+if ($useModule)
+{
+    $m = New-Module {
+        function Test-DrivePresenceFromModule
+        {
+            param ([String]$Path)
+
+            & $global:CoreScriptPath -Path $Path
+        }
+
+        Export-ModuleMember -Function Test-DrivePresenceFromModule
+    }
+}
+
+try
+{
+    if ($useModule)
+    {
+        Import-Module $m -Force
+        Test-DrivePresenceFromModule -Path $FullPath
+    }
+    else
+    {
+        & $global:CoreScriptPath -Path $FullPath
+    }
+}
+finally
+{
+    if ($useModule)
+    {
+        Remove-Module $m
+    }
+}

test/powershell/Provider/AutomountSubstDriveCore.ps1

@@ -0,0 +1,31 @@
+param ([String]$Path)
+
+try
+{
+    # Get a drive letter between F and Y that is not being used for the drive name.
+    $driveLetter = [char[]](70..89) | Where-Object {$_ -notin (Get-PSDrive).Name} | Select-Object -Last 1
+
+    $dir = New-Item $Path -ItemType Directory -Force
+
+    # Create virtual drive pointing to the parent of the directory
+    subst.exe "$driveLetter`:" $dir.Parent.FullName
+    $exitCode = $LASTEXITCODE
+    if ($exitCode -ne 0) { Write-Error "Creating drive with subst.exe failed with exit code $exitCode" }
+
+    $root = [String]::Format('{0}:\', $driveLetter)
+    $pathToCheck = Join-Path -Path $root -ChildPath $dir.Name
+
+    if (Test-Path $pathToCheck)
+    {
+        "Drive found"
+        if (-not (Get-PSDrive -Name $driveLetter -Scope Global -ErrorAction SilentlyContinue))
+        {
+            Write-Error "Drive is NOT in Global scope"
+        }
+    }
+    else { Write-Error "$pathToCheck not found" }
+}
+finally
+{
+    subst.exe "$driveLetter`:" /d
+}

test/powershell/Provider/AutomountVHDDrive.ps1

@@ -0,0 +1,76 @@
+# Precondition: start from fresh PS session, do not have the media mounted
+param([switch]$useModule, [string]$VHDPath)
+
+function CreateVHD ($VHDPath, $Size)
+{
+  $drive = (New-VHD -path $vhdpath -SizeBytes $size -Dynamic   | `
+              Mount-VHD -Passthru |  `
+              get-disk -number {$_.DiskNumber} | `
+              Initialize-Disk -PartitionStyle MBR -PassThru | `
+              New-Partition -UseMaximumSize -AssignDriveLetter:$False -MbrType IFS | `
+              Format-Volume -Confirm:$false -FileSystem NTFS -force | `
+              get-partition | `
+              Add-PartitionAccessPath -AssignDriveLetter -PassThru | `
+              get-volume).DriveLetter
+
+    $drive
+}
+
+if ($useModule)
+{
+    $m = New-Module {
+        function Test-DrivePresenceFromModule
+        {
+            param ([String]$Path)
+
+            if (Test-Path $Path)
+            {
+                "Drive found"
+                if (-not (Get-PSDrive -Name $Path[0] -Scope Global -ErrorAction SilentlyContinue))
+                {
+                    Write-Error "Drive is NOT in Global scope"
+                }
+            }
+            else { Write-Error "$Path not found" }
+        }
+
+        Export-ModuleMember -Function Test-DrivePresenceFromModule
+    }
+}
+
+try
+{
+    if ($useModule)
+    {
+        Import-Module $m -Force
+    }
+
+    $drive = CreateVHD -VHDPath $VHDPath -Size 5mb
+    $pathToCheck = "${drive}:"
+    
+    if ($useModule)
+    {
+        Test-DrivePresenceFromModule -Path $pathToCheck
+    }
+    else
+    {
+        if (Test-Path $pathToCheck)
+        {
+            "Drive found"
+            if (-not (Get-PSDrive -Name $drive -Scope Global -ErrorAction SilentlyContinue))
+            {
+                Write-Error "Drive is NOT in Global scope"
+            }
+        }
+        else { Write-Error "$pathToCheck not found" }
+    }
+}
+finally
+{
+    if ($useModule)
+    {
+        Remove-Module $m
+    }
+    Dismount-VHD $VHDPath
+    Remove-Item $VHDPath
+}

test/powershell/Provider/Pester.AutomountedDrives.Tests.ps1

@@ -0,0 +1,55 @@
+<############################################################################################ 
+ # File: Pester.AutomountedDrives.Tests.ps1
+ # Pester.AutomountedDrives.Tests suite contains Tests that are
+ # used for validating automounted PowerShell drives.
+ ############################################################################################>
+$script:TestSourceRoot = $PSScriptRoot
+Describe "Test suite for validating automounted PowerShell drives" -Tags "CI","Slow" {
+
+    BeforeAll {
+        $powershell = Join-Path -Path $PsHome -ChildPath "powershell"
+        
+        $AutomountVHDDriveScriptPath = Join-Path $script:TestSourceRoot 'AutomountVHDDrive.ps1'
+        $vhdPath = Join-Path $TestDrive 'TestAutomountVHD.vhd'
+
+        $AutomountSubstDriveScriptPath = Join-Path $script:TestSourceRoot 'AutomountSubstDrive.ps1'
+        $substDir = Join-Path (Join-Path $TestDrive 'TestAutomountSubstDrive') 'TestDriveRoot'
+        New-Item $substDir -ItemType Directory -Force | Out-Null
+
+        $SubstNotFound = $false
+        try { subst.exe } catch { $SubstNotFound = $true }
+
+        $VHDToolsNotFound = $false
+        try
+        {
+            $tmpVhdPath = Join-Path $TestDrive 'TestVHD.vhd'
+            New-VHD -path $tmpVhdPath -SizeBytes 5mb -Dynamic -ErrorAction Stop
+            Remove-Item $tmpVhdPath
+        }
+        catch
+        { $VHDToolsNotFound = $true }
+    }
+    
+    Context "Validating automounting FileSystem drives" {
+        
+        It "Test automounting using subst.exe" -Skip:$SubstNotFound {
+           & $powershell -noprofile -command "& '$AutomountSubstDriveScriptPath' -FullPath '$substDir'" | Should Be "Drive found"
+        }
+     
+        It "Test automounting using New-VHD/Mount-VHD" -Skip:$VHDToolsNotFound {
+            & $powershell -noprofile -command "& '$AutomountVHDDriveScriptPath' -VHDPath '$vhdPath'" | Should Be "Drive found"
+        }
+    }
+
+    Context "Validating automounting FileSystem drives from modules" {
+        
+        It "Test automounting using subst.exe" -Skip:$SubstNotFound {
+           & $powershell -noprofile -command "& '$AutomountSubstDriveScriptPath' -useModule -FullPath '$substDir'" | Should Be "Drive found"
+        }
+        
+        It "Test automounting using New-VHD/Mount-VHD" -Skip:$VHDToolsNotFound {
+            $vhdPath = Join-Path $TestDrive 'TestAutomountVHD.vhd'
+            & $powershell -noprofile -command "& '$AutomountVHDDriveScriptPath' -useModule -VHDPath '$vhdPath'" | Should Be "Drive found"
+        }
+    }
+}