Clean up workflow logic in the module loading component (#6523)

Clean up workflow logic in the module loading component.
Workflow module is not supported in PSCore.
Currently, Import-Module throws a terminating error when seeing .xaml modules. After the change, Import-Module throws a non-terminating error when seeing .xaml modules.

test/powershell/Modules/Microsoft.PowerShell.Core/Import-Module.Tests.ps1

@@ -146,7 +146,7 @@ namespace ModuleCmdlets
 
         $psdFile = Join-Path $TESTDRIVE test.psd1
         $nestedModule = Join-Path NOExistedPath Microsoft.PowerShell.Commands.Utility.dll
-        New-ModuleManifest -Path $psdFile -NestedModules $nestedModule 
+        New-ModuleManifest -Path $psdFile -NestedModules $nestedModule
         try
         {
             $module = Import-Module $psdFile -PassThru
@@ -158,7 +158,7 @@ namespace ModuleCmdlets
         {
             Remove-Module $module -ErrorAction SilentlyContinue
         }
-        
+
     }
  }
 
@@ -200,3 +200,34 @@ Describe "Import-Module should be case insensitive" -Tags 'CI' {
         Get-Module tESTmODULE | Should -BeNullOrEmpty
     }
 }
+
+Describe "Workflow .Xaml module is not supported in PSCore" -tags "Feature" {
+    BeforeAll {
+        $xamlFile = Join-Path $TestDrive "XamlTest.xaml"
+        New-Item -Path $xamlFile -ItemType File -Force
+
+        $xamlRootModule = Join-Path $TestDrive "XamlRootModule"
+        New-Item -Path $xamlRootModule -ItemType Directory -Force
+        Copy-Item $xamlFile $xamlRootModule
+        $xamlRootModuleManifest = Join-Path $xamlRootModule "XamlRootModule.psd1"
+        New-ModuleManifest -Path $xamlRootModuleManifest -RootModule "XamlTest.xaml"
+
+        $xamlNestedModule = Join-Path $TestDrive "XamlNestedModule"
+        New-Item -Path $xamlNestedModule -ItemType Directory -Force
+        Copy-Item $xamlFile $xamlNestedModule
+        $xamlNestedModuleManifest = Join-Path $xamlNestedModule "XamlNestedModule.psd1"
+        New-ModuleManifest -Path $xamlNestedModuleManifest -NestedModules "XamlTest.xaml"
+    }
+
+    It "Import a XAML file directly should raise a 'NotSupported' error" {
+        { Import-Module $xamlFile -ErrorAction Stop } | Should -Throw -ErrorId "Modules_WorkflowModuleNotSupported,Microsoft.PowerShell.Commands.ImportModuleCommand"
+    }
+
+    It "Import a module with XAML root module should raise a 'NotSupportd' error" {
+        { Import-Module $xamlRootModule -ErrorAction Stop } | Should -Throw -ErrorId "Modules_WorkflowModuleNotSupported,Microsoft.PowerShell.Commands.ImportModuleCommand"
+    }
+
+    It "Import a module with XAML nested module should raise a 'NotSupported' error" {
+        { Import-Module $xamlNestedModule -ErrorAction Stop } | Should -Throw -ErrorId "Modules_WorkflowModuleNotSupported,Microsoft.PowerShell.Commands.ImportModuleCommand"
+    }
+}

test/powershell/engine/Module/TestModuleManifest.Tests.ps1

@@ -69,7 +69,7 @@ Describe "Test-ModuleManifest tests" -tags "CI" {
 
     It "module manifest containing valid processed empty rootmodule file type fails: <rootModuleValue>" -TestCases (
         @{rootModuleValue = "foo.cdxml"; error = "System.Xml.XmlException"},  # fails when cmdlet tries to read it as XML
-        @{rootModuleValue = "foo.xaml"; error = "NotSupported"}   # not supported on PowerShell Core
+        @{rootModuleValue = "foo.xaml"; error = "Modules_WorkflowModuleNotSupported"}   # not supported on PowerShell Core
     ) {
 
         param($rootModuleValue, $error)
@@ -231,7 +231,7 @@ Describe "Test-ModuleManifest Performance bug followup" -tags "CI" {
     It "Test-ModuleManifest should not load unnessary modules" {
 
         $job = start-job -name "job1" -ScriptBlock {test-modulemanifest "$using:UserModulesPath\ModuleWithDependencies2\2.0\ModuleWithDependencies2.psd1" -verbose} | Wait-Job
-        
+
         $verbose = $job.ChildJobs[0].Verbose.ReadAll()
         # Before the fix, all modules under $pshome will be imported and will be far more than 15 verbose messages. However, we cannot fix the number in case verbose message may vary.
         $verbose.Count | Should -BeLessThan 15