SqlServerDsc: Improvement to how Import-SQLPSModule import module

CHANGELOG.md

@@ -6,6 +6,12 @@
   - Updated helper function Restart-SqlService to have to new optional parameters
     `SkipClusterCheck` and `SkipWaitForOnline`. This was to support more aspects
     of the resource SqlServerNetwork.
+  - Updated helper function `Import-SQLPSModule`
+    - To only import module if the
+      module does not exist in the session.
+    - To always import the latest version of 'SqlServer' or 'SQLPS' module, if
+      more than one version exist on the target node. It will still prefer to
+      use 'SqlServer' module.
 - Changes to SqlAlwaysOnService
   - Integration tests was updated to handle new IPv6 addresses on the AppVeyor
     build worker ([issue #1155](https://github.com/PowerShell/SqlServerDsc/issues/1155)).
@@ -15,6 +21,13 @@
     enabling and disabling the protocol.
   - Added integration tests for this resource
     ([issue #751](https://github.com/PowerShell/SqlServerDsc/issues/751)).
+- Changes to SqlAG
+  - Removed excess `Import-SQLPSModule` call.
+- Changes to SqlSetup
+  - Now after a successful install the "SQL PowerShell module" is reevaluated and
+    forced to be reimported into the session. This is to support that a never
+    version of SQL Server was installed side-by-side so that SQLPS module should
+    be used instead.
 
 ## 11.3.0.0
 

DSCResources/MSFT_SqlAG/MSFT_SqlAG.psm1

@@ -232,8 +232,6 @@ function Set-TargetResource
         $ProcessOnlyOnActiveNode
     )
 
-    Import-SQLPSModule
-
     # Connect to the instance
     $serverObject = Connect-SQL -SQLServer $ServerName -SQLInstanceName $InstanceName
 

DSCResources/MSFT_SqlSetup/MSFT_SqlSetup.psm1

@@ -1420,8 +1420,9 @@ function Set-TargetResource
         elseif ($processExitCode -ne 0)
         {
             $setupExitMessageError = ('{0} {1}' -f $setupExitMessage, ($script:localizedData.SetupFailed))
-
             Write-Warning $setupExitMessageError
+
+            $setupEndedInError = $true
         }
         else
         {
@@ -1436,13 +1437,35 @@ function Set-TargetResource
             {
                 Write-Verbose -Message $script:localizedData.Reboot
 
+                # Rebooting, so no point in refreshing the session.
+                $forceReloadPowerShellModule = $false
+
                 $global:DSCMachineStatus = 1
             }
             else
             {
                 Write-Verbose -Message $script:localizedData.SuppressReboot
+                $forceReloadPowerShellModule = $true
             }
         }
+        else
+        {
+            $forceReloadPowerShellModule = $true
+        }
+
+        if ((-not $setupEndedInError) -and $forceReloadPowerShellModule)
+        {
+            <#
+                Force reload of SQLPS module in case a newer version of
+                SQL Server was installed that contains a newer version
+                of the SQLPS module, although if SqlServer module exist
+                on the target node, that will be used regardless.
+                This is to make sure we use the latest SQLPS module that
+                matches the latest assemblies in GAC, mitigating for example
+                issue #1151.
+            #>
+            Import-SQLPSModule -Force
+        }
 
         if (-not (Test-TargetResource @PSBoundParameters))
         {