Install-DbaMaintenanceSolution: make off switches work and increase test coverage (#10172)

Author: ReeceGoding

public/Install-DbaMaintenanceSolution.ps1

@@ -102,7 +102,7 @@ function Install-DbaMaintenanceSolution {
         Only applies when InstallJobs is specified.
 
     .PARAMETER ModificationLevel
-        Specifies minimum modification percentage required before ChangeBackupType converts a differential or log backup to full backup.
+        Specifies minimum modification percentage required before ChangeBackupType converts a differential backup to full backup.
         Valid range: 0-100. Use this with ChangeBackupType to control when backup type changes occur based on data modification levels.
         Only applies when InstallJobs is specified.
 
@@ -312,6 +312,11 @@ function Install-DbaMaintenanceSolution {
             return
         }
 
+        if ($BackupLocation -eq "NUL" -and $Verify) {
+            Stop-Function -Message "Verify is not supported when backing up to NUL. Either backup to a different directory or turn off Verify."
+            return
+        }
+
         if ((Test-Bound -ParameterName CleanupTime) -and -not $InstallJobs) {
             Stop-Function -Message "CleanupTime is only useful when installing jobs. To install jobs, please use '-InstallJobs' in addition to CleanupTime."
             return
@@ -729,7 +734,7 @@ function Install-DbaMaintenanceSolution {
             }
 
             # Modify backup job steps to include additional parameters
-            if ($InstallJobs -and ($ChangeBackupType -or $Compress -or $CopyOnly -or $Verify -or $CheckSum -or $ModificationLevel)) {
+            if ($InstallJobs) {
                 Write-ProgressHelper -ExcludePercent -Message "Applying additional backup parameters to job steps"
 
                 $null = $server.Refresh()
@@ -756,17 +761,23 @@ function Install-DbaMaintenanceSolution {
                         }
 
                         # Add ModificationLevel parameter for jobs with ChangeBackupType
-                        if ($ModificationLevel -gt 0 -and ($job.Name -match "DIFF|LOG")) {
+                        if ($ModificationLevel -gt 0 -and ($job.Name -match "DIFF")) {
                             if ($modifiedCommand -notmatch "@ModificationLevel") {
                                 $modifiedCommand = $modifiedCommand -replace "(@LogToTable = '[YN]')", "`$1,$([System.Environment]::NewLine)@ModificationLevel = $ModificationLevel"
                             }
                         }
 
                         # Add Compress parameter for all backup jobs
                         if ($Compress) {
+                            $modifiedCommand = $modifiedCommand -replace "@Compress = 'N'", "@Compress = 'Y'"
                             if ($modifiedCommand -notmatch "@Compress") {
                                 $modifiedCommand = $modifiedCommand -replace "(@LogToTable = '[YN]')", "`$1,$([System.Environment]::NewLine)@Compress = 'Y'"
                             }
+                        } else {
+                            $modifiedCommand = $modifiedCommand -replace "@Compress = 'Y'", "@Compress = 'N'"
+                            if ($modifiedCommand -notmatch "@Compress") {
+                                $modifiedCommand = $modifiedCommand -replace "(@LogToTable = '[YN]')", "`$1,$([System.Environment]::NewLine)@Compress = 'N'"
+                            }                        
                         }
 
                         # Add CopyOnly parameter for all backup jobs
@@ -777,16 +788,18 @@ function Install-DbaMaintenanceSolution {
                         }
 
                         # Add Verify parameter for all backup jobs
-                        if ($Verify) {
-                            if ($modifiedCommand -notmatch "@Verify") {
-                                $modifiedCommand = $modifiedCommand -replace "(@LogToTable = '[YN]')", "`$1,$([System.Environment]::NewLine)@Verify = 'Y'"
+                        # Ola turns this on by default, so all we have to do is turn it off if asked.
+                        if (-not $Verify) {
+                            if ($modifiedCommand -notmatch "@Verify = 'N'") {
+                                $modifiedCommand = $modifiedCommand -replace "@Verify = 'Y'", "@Verify = 'N'"
                             }
                         }
 
                         # Add CheckSum parameter for all backup jobs
-                        if ($CheckSum) {
-                            if ($modifiedCommand -notmatch "@CheckSum") {
-                                $modifiedCommand = $modifiedCommand -replace "(@LogToTable = '[YN]')", "`$1,$([System.Environment]::NewLine)@CheckSum = 'Y'"
+                        # Ola turns this on by default, so all we have to do is turn it off if asked.
+                        if (-not $CheckSum) {
+                            if ($modifiedCommand -notmatch "@CheckSum = 'N'") {
+                                $modifiedCommand = $modifiedCommand -replace "@CheckSum = 'Y'", "@CheckSum = 'N'"
                             }
                         }
 
@@ -823,4 +836,4 @@ function Install-DbaMaintenanceSolution {
         Write-ProgressHelper -ExcludePercent -Message "Installation complete"
         Write-ProgressHelper -Completed
     }
-}
+}