xSQLServerRSConfig: Returns wrong value ($null) from Test-TargetResource

[johlju]

Details of the scenario you tried and the problem that is occurring:
When Reporting Services are not initialized then function Test-TargetResource is returning $null instead of $false.

VERBOSE: [APPVYR-WIN]: LCM:  [ Start  Resource ]  [[xSQLServerRSConfig]Integration_Test]
VERBOSE: [APPVYR-WIN]: LCM:  [ Start  Test     ]  [[xSQLServerRSConfig]Integration_Test]
VERBOSE: [APPVYR-WIN]: LCM:  [ End    Test     ]  [[xSQLServerRSConfig]Integration_Test]  in 0.2390 seconds.
The PowerShell DSC resource C:\projects\xsqlserver\DscResources\MSFT_xSQLServerRSConfig returned results in a format that is not valid. The results from running Test-TargetResource must be the boolean value True or False.
    + CategoryInfo          : InvalidResult: (:) [], CimException
    + FullyQualifiedErrorId : TestTargetResourceInvalidResultFormat
    + PSComputerName        : localhost
 
VERBOSE: [APPVYR-WIN]: LCM:  [ End    Set      ]
The SendConfigurationApply function did not succeed.
    + CategoryInfo          : NotImplemented: (root/Microsoft/...gurationManager:String) [], CimException
    + FullyQualifiedErrorId : MI RESULT 7
    + PSComputerName        : localhost
 
VERBOSE: Operation 'Invoke CimMethod' complete.
VERBOSE: Time taken for configuration job to complete is 74.548 seconds

The code here should handle a $null value.

https://github.com/PowerShell/xSQLServer/blob/b2e553b2a2638fc88df1e815e4867f3733c7eed6/DSCResources/MSFT_xSQLServerRSConfig/MSFT_xSQLServerRSConfig.psm1#L56

The DSC configuration that is using the resource (as detailed as possible):

xSQLServerRSConfig 'Integration_Test'
{
    # Instance name for the Reporting Services.
    InstanceName         = $Node.InstanceName

    <#
        Instance for Reporting Services databases.
        Note: This instance is created in a prior integration test.
    #>
    RSSQLServer          = $Node.RSSQLServer
    RSSQLInstanceName    = $Node.RSSQLInstanceName

    PsDscRunAsCredential = $SqlAdministratorCredential   # <--- DID NOT HAVE WMI RIGHTS

    DependsOn            = @(
        '[xSQLServerSetup]InstallReportingServicesInstance'
    )
}

Version of the Operating System, SQL Server and PowerShell the DSC Target Node is running:
Windows Server 2016, SQL Server 2016, WMF 5.1

What module (SqlServer or SQLPS) and which version of the module the DSC Target Node is running:
SQLPS

Version of the DSC module you're using, or 'dev' if you're using current dev branch:
Dev