Cleanup, output and -WhatIf - Fix the side findings of the progress work in 10 commands

public/Install-DbaInstance.ps1

@@ -566,8 +566,17 @@ function Install-DbaInstance {
                 }
                 # resolve names
                 Write-ProgressHelper -TotalSteps $totalSteps -Activity $activity -StepNumber ($stepCounter++) -Message "Resolving computer name"
-                $resolvedName = Resolve-DbaNetworkName -ComputerName $computer -Credential $Credential
-                if ($computer.IsLocalHost) {
+                # Without a resolved name, the name given is used, as Update-DbaInstance does. An empty name made every
+                # later step fail on it, starting with the check for a pending reboot.
+                try {
+                    $resolvedName = Resolve-DbaNetworkName -ComputerName $computer -Credential $Credential -EnableException
+                } catch {
+                    Write-Message -Level Verbose -Message "Could not resolve $($computer.ComputerName) (this may occur with CredSSP or workgroup environments). Using provided name directly."
+                    $resolvedName = $null
+                }
+                if (-not $resolvedName) {
+                    $fullComputerName = $computer.ComputerName
+                } elseif ($computer.IsLocalHost) {
                     # Don't add a domain to localhost as this might add a domain that is later not recognized by .IsLocalHost anymore (#6976).
                     $fullComputerName = $resolvedName.ComputerName
                 } else {

public/Install-DbaSqlPackage.ps1

@@ -212,7 +212,8 @@ function Install-DbaSqlPackage {
             }
 
             # Download if needed
-            if (-not (Test-Path -Path $LocalFile) -or $Force) {
+            # The download is real work, so -WhatIf has to skip it too, and not only the installation.
+            if ((-not (Test-Path -Path $LocalFile) -or $Force) -and $Pscmdlet.ShouldProcess($url, "Download SqlPackage to $LocalFile")) {
                 try {
                     Write-Progress -Activity "Installing SqlPackage" -Status "Starting download from Microsoft..." -PercentComplete 20
                     Write-Message -Level Verbose -Message "Downloading SqlPackage from $url"
@@ -290,6 +291,12 @@ function Install-DbaSqlPackage {
                 }
             }
 
+            # With -WhatIf nothing was downloaded or installed, so there is nothing to verify. The verification warned that
+            # the installation failed when SqlPackage was not there yet.
+            if ($WhatIfPreference) {
+                return
+            }
+
             Write-Progress -Activity "Installing SqlPackage" -Status "Verifying installation..." -PercentComplete 90
 
             # Verify installation

public/Invoke-DbaAdvancedInstall.ps1

@@ -232,7 +232,7 @@ function Invoke-DbaAdvancedInstall {
             $restartNeeded = Test-PendingReboot -ComputerName $ComputerName -Credential $Credential -NoPendingRename:$NoPendingRenameCheck
         } catch {
             $restartNeeded = $false
-            Stop-Function -Message "Failed to get reboot status from $computer" -ErrorRecord $_
+            Stop-Function -Message "Failed to get reboot status from $ComputerName" -ErrorRecord $_
         }
         if ($restartNeeded -and $Restart) {
             # Restart the computer prior to doing anything
@@ -282,8 +282,17 @@ function Invoke-DbaAdvancedInstall {
                 $null = Send-File -Path $ConfigurationPath -Destination $chosenPath -Session $session -ErrorAction Stop
                 $session | Remove-PSSession
             } catch {
-                Stop-Function -Message "Failed to copy file $($ConfigurationPath) to $remoteConfig on $($ComputerName), exiting" -ErrorRecord $_
-                return
+                # Like the other failures below, this one returns its result object, so the caller gets a result for the
+                # computer. The session and the local configuration file are cleaned up here, because the cleanup in the
+                # finally of the installation is not reached from here.
+                $msg = "Failed to copy file $($ConfigurationPath) to $remoteConfig on $($ComputerName), exiting"
+                Stop-Function -Message $msg -ErrorRecord $_
+                $output.Notes += $msg
+                if ($session) {
+                    $session | Remove-PSSession
+                }
+                Remove-Item -Path $ConfigurationPath -ErrorAction SilentlyContinue
+                return $output
             }
         }
         $installParams = $ArgumentList

public/Invoke-DbaAdvancedRestore.ps1

@@ -542,14 +542,15 @@ function Invoke-DbaAdvancedRestore {
                                 Write-Progress -id 1 -activity "Verifying $database backup file on $SqlInstance - Backup $BackupCnt of $($Backups.count)" -percentcomplete 0 -status ([System.String]::Format("Progress: {0} %", 0))
                                 $verify = $restore.SqlVerify($server)
                                 Write-Progress -id 1 -activity "Verifying $database backup file on $SqlInstance - Backup $BackupCnt of $($Backups.count)" -status "Complete" -Completed
+                                # No return here: it left the whole end block, so only the first backup file was verified.
                                 if ($verify) {
                                     Write-Message -Message "VerifyOnly restore Succeeded" -Level Verbose
                                     $restoreComplete = $true
-                                    return "Verify successful"
+                                    "Verify successful"
                                 } else {
                                     Write-Message -Message "VerifyOnly restore Failed" -Level Warning
                                     $restoreComplete = $False
-                                    return "Verify failed"
+                                    "Verify failed"
                                 }
                             } else {
                                 $outerProgress = $BackupCnt / $Backups.Count * 100
@@ -616,7 +617,9 @@ function Invoke-DbaAdvancedRestore {
                             Write-Message -Level Verbose -Message "Failed to restore $database"
                             $restoreComplete = $False
                             $ExitError = $_.Exception.InnerException
-                            Stop-Function -Message "Failed to restore db $database, stopping" -ErrorRecord $_ -Continue
+                            # No -Continue: it continued with the next backup file of this database, so the break that
+                            # stops the database and goes on with the next one was never reached.
+                            Stop-Function -Message "Failed to restore db $database, stopping" -ErrorRecord $_
                             break
                         } finally {
                             # The bar of this backup file ends with the file, also when its restore failed or was stopped.

public/Invoke-DbaDbDataGenerator.ps1

@@ -595,12 +595,14 @@ function Invoke-DbaDbDataGenerator {
                 }
             } finally {
                 Write-ProgressHelper -Completed
-            }
-
-            try {
-                $sqlconn.Close()
-            } catch {
-                Stop-Function -Message "Failure" -Continue -ErrorRecord $_
+                # The returns above, a throw under EnableException and a stopped pipeline skip everything after this
+                # block, so the connection is closed here. A warning instead of Stop-Function, because a throw from a
+                # finally would replace the error that is on its way out.
+                try {
+                    $sqlconn.Close()
+                } catch {
+                    Write-Message -Level Warning -Message "Failure closing the connection to $instance" -ErrorRecord $_
+                }
             }
         }
     }