SqlAGReplica: Test doesn't check ReadOnlyRoutingList properly

[codykonior]

Details of the scenario you tried and the problem that is occurring

$configurationData = @{
    AllNodes = @(
        @{
            NodeName = '*'
            PsDscAllowPlainTextPassword = $true
            PsDscAllowDomainUser = $true
        }
        @{
         NodeName = 'localhost'
        }
    )
}

configuration Blah {
    param(
        $Credential
    )
    Import-DscResource -Module SqlServerDsc

    Node $AllNodes.NodeName {    
        SqlAGReplica SEC1N1 {
            ServerName = 'SEC1N1'
            InstanceName = 'MSSQLSERVER'

            AvailabilityGroupName = 'AG1'
            Name = 'SEC1N1'
            ReadOnlyRoutingConnectionUrl = 'tcp://SEC1N1.lab.com:1433'
            ReadOnlyRoutingList = 'SEC1N2', 'SEC1N3'
            PsDscRunAsCredential = $Credential
        }
    }
}

if (!$credential) { $credential = Get-Credential LAB\LocalAdministrator }
Blah -Credential $credential -ConfigurationData $configurationData
Start-DscConfiguration -Force -Wait -Verbose -Path Blah

Although ReadOnlyRoutingList gets set properly, if you run the code a second time you get this result.

VERBOSE: [CHWK01]: LCM:  [ Start  Test     ]  [[SqlAGReplica]SEC1N1]
VERBOSE: [CHWK01]:                            [[SqlAGReplica]SEC1N1] Importing the module MSFT_SqlAGReplica in force mode.
VERBOSE: [CHWK01]:                            [[SqlAGReplica]SEC1N1] Importing the module MSFT_SqlAGReplica in force mode.
VERBOSE: [CHWK01]:                            [[SqlAGReplica]SEC1N1] Preferred module SqlServer found.
VERBOSE: [CHWK01]:                            [[SqlAGReplica]SEC1N1] Importing PowerShell module 'SqlServer' with version '21.0.17279' from path 'C:\Program Files\WindowsPowerShell\Modules\SqlServer\SqlServer.psm1'.
VERBOSE: [CHWK01]:                            [[SqlAGReplica]SEC1N1] Connected to SQL instance 'SEC1N1'.
VERBOSE: [CHWK01]:                            [[SqlAGReplica]SEC1N1] 2019-03-14_00-14-48: 'ReadOnlyRoutingList' should be 'SEC1N2 SEC1N3' but is 'SEC1N2 SEC1N3'

It will trigger Set again, which does nothing, and so never reaches desired state.

Suggested solution to the issue

In the Test code there's a -ne comparison which isn't valid for the ReadOnlyRoutingList being a string array (it's the only one).

                    if ( $getTargetResourceResult.($parameterName) -ne $parameterValue )
                    {
                        New-VerboseMessage -Message "'$($parameterName)' should be '$($parameterValue)' but is '$($getTargetResourceResult.($parameterName))'"

                        $result = $False
                    }

To fix this the ReadOnlyRoutingList parameter can have an explicit different case that uses a string join with commas instead of the -ne comparison. That's how it's done in the Set portion and that bit is working great.

                    if ( ( $submittedParameters -contains 'ReadOnlyRoutingList' ) -and ( ( $ReadOnlyRoutingList -join ',' ) -ne ( $availabilityGroupReplica.ReadOnlyRoutingList -join ',' ) ) )

Version of the DSC module that was used ('dev' if using current dev branch)

dev