tests/Test-CmClientMissing.ps1

function Test-CmClientMissing {
    [CmdletBinding()]
    param (
        [parameter()][string] $TestName = "Test-CmClientMissing",
        [parameter()][string] $TestGroup = "operation",
        [parameter()][string] $Description = "Check for discovered machines without a client",
        [parameter()][hashtable] $ScriptParams
    )
    try {
        [System.Collections.Generic.List[PSObject]]$tempdata = @() # for detailed test output to return if needed
        $stat = "PASS" # do not change this
        $msg  = "No issues found" # do not change this either
        $query = "SELECT DISTINCT
fcm.ResourceID,
fcm.Name,
fcm.SiteCode,
fcm.Domain,
sys.Operating_System_Name_and0
FROM v_FullCollectionMembership fcm
INNER JOIN v_R_System sys ON fcm.ResourceID = sys.ResourceID
WHERE fcm.IsClient != 1 AND fcm.Name NOT LIKE '%Unknown%' AND fcm.CollectionID = 'SMS00001'
AND sys.Operating_System_Name_and0 IS NOT NULL AND sys.Operating_System_Name_and0 <> ''"

        if ($ScriptParams.Credential) {
            $res = @(Invoke-DbaQuery -SqlInstance $ScriptParams.SqlInstance -Database $ScriptParams.Database -Query $query -SqlCredential $ScriptParams.Credential)
        } else {
            $res = @(Invoke-DbaQuery -SqlInstance $ScriptParams.SqlInstance -Database $ScriptParams.Database -Query $query)
        }
        if ($null -ne $res -and $res.Count -gt 0) {
            $stat = "WARNING" # or "FAIL"
            $msg  = "$($res.Count) items found: $($res.Name -join ',')"
            $res | Foreach-Object {$tempdata.Add("Name=$($_.Name),SiteCode=$($_.SiteCode)")}
        }
    }
    catch {
        $stat = 'ERROR'
        $msg = $_.Exception.Message -join ';'
    }
    finally {
        Write-Output $([pscustomobject]@{
            TestName    = $TestName
            TestGroup   = $TestGroup
            TestData    = $tempdata
            Description = $Description
            Status      = $stat 
            Message     = $msg
            Credential  = $(if($ScriptParams.Credential){$($ScriptParams.Credential).UserName} else { $env:USERNAME })
        })
    }
}