Add warning about embedded resources (#35)

Author: TravisEz13

src/PSDesiredStateConfiguration/PSDesiredStateConfiguration.psm1

@@ -66,6 +66,7 @@ data LocalizedData
     ImportDscResourceWarningForInbuiltResource=The configuration '{0}' is loading one or more built-in resources without explicitly importing associated modules. Add Import-DscResource -ModuleName 'PSDesiredStateConfiguration' to your configuration to avoid this message.
     PasswordTooLong=An error occurred during encryption of a password in node '{0}'. Most likely the password entered is too long to be encrypted using the selected certificate.  Please either use a shorter password or select a certificate with a larger key.
     PsDscRunAsCredentialNotSupport=The 'PsDscRunAsCredential' property is not currently support when using Invoke-DscResource.
+    EmbeddedResourcesNotSupported=Embedded resources are not support on Linux or macOS.  Please see https://aka.ms/PSCoreDSC for more details.
 '@
 }
 Set-StrictMode -Off
@@ -1904,6 +1905,10 @@ function Configuration
         return $moduleInfos
     }
 
+    if ( $IsMacOS -or $IsLinux ) {
+        Write-Warning -Message $LocalizedData.EmbeddedResourcesNotSupported
+    }
+
     try
     {
         Write-Debug -Message "BEGIN CONFIGURATION '$Name' PROCESSING: OutputPath: '$OutputPath'"
@@ -4687,6 +4692,10 @@ function Invoke-DscResource
         ThrowError -ExceptionName 'System.ArgumentException' -ExceptionMessage $errorMessage -ExceptionObject $exception -ErrorId 'InvalidResourceSpecification,Invoke-DscResource' -ErrorCategory InvalidArgument
     }
 
+    if ( @($resource.Properties | Where-Object { $_.PropertyType -eq '' }).Count -gt 0 -and ($IsMacOS -or $IsLinux)) {
+        Write-Warning -Message $LocalizedData.EmbeddedResourcesNotSupported
+    }
+
     [Microsoft.PowerShell.DesiredStateConfiguration.DscResourceInfo] $resource = $resource[0]
     if($resource.ImplementedAs -ne 'PowerShell')
     {

test/PSDesiredStateConfiguration.Tests.ps1

@@ -368,6 +368,7 @@ Describe "Test PSDesiredStateConfiguration" -tags CI {
                 )
 
                 Install-ModuleIfMissing -Name PowerShellGet -Force -SkipPublisherCheck -MinimumVersion '2.2.1'
+                Install-ModuleIfMissing -Name xWebAdministration
                 $module = Get-Module PowerShellGet -ListAvailable | Sort-Object -Property Version -Descending | Select-Object -First 1
 
                 $psGetModuleSpecification = @{ModuleName = $module.Name; ModuleVersion = $module.Version.ToString() }
@@ -428,6 +429,34 @@ Describe "Test PSDesiredStateConfiguration" -tags CI {
                 Should -Throw -ErrorId 'InvalidResourceSpecification,Invoke-DscResource' -ExpectedMessage 'Invalid Resource Name ''Script'' or module specification.'
             }
 
+            it "Resource with embedded resource not supported and a warning should be produced"  {
+
+                if (!(Test-IsInvokeDscResourceEnable)) {
+                    Set-ItResult -Skipped -Because "Feature not enabled"
+                }
+
+                if (!$IsMacOS) {
+                    Set-ItResult -Skipped -Because "Not applicable on Windows and xWebAdministration resources don't load on linux"
+                }
+
+                try {
+                    Invoke-DscResource -Name xWebSite -ModuleName 'xWebAdministration' -Method Test -Property @{TestScript = 'foobar' } -ErrorAction Stop -WarningVariable warnings
+                }
+                catch{
+                    #this will fail too, but that is nat what we are testing...
+                }
+
+                $warnings.Count | Should -Be 1 -because "There should be 1 warning on macOS and Linux"
+                $warnings[0] | Should -Match 'embedded resources.*not support'
+            }
+
+            it "Using PsDscRunAsCredential should say not supported" -Skip:(!(Test-IsInvokeDscResourceEnable)) {
+                {
+                    Invoke-DscResource -Name Script -ModuleName PSDscResources -Method Set -Property @{TestScript = { Write-Output 'test'; return $false }; GetScript = { return @{ } }; SetScript = {return}; PsDscRunAsCredential='natoheu'}  -ErrorAction Stop
+                } |
+                Should -Throw -ErrorId 'PsDscRunAsCredentialNotSupport,Invoke-DscResource'
+            }
+
             # waiting on Get-DscResource to be fixed
             it "Invalid module name" -Skip:(!(Test-IsInvokeDscResourceEnable)) {
                 Set-ItResult -Pending -Because "https://github.com/PowerShell/PSDesiredStateConfiguration/issues/17"