tests/Test-CmDpNoGroups.ps1

function Test-CmDpNoGroups {
    [CmdletBinding()]
    param (
        [parameter()][string] $TestName = "DP Servers Not in a DP Group",
        [parameter()][string] $TestGroup = "configuration",
        [parameter()][string] $Description = "Check for DPs which are not in a DP group",
        [parameter()][hashtable] $ScriptParams
    )
    try {
        $startTime = (Get-Date)
        [System.Collections.Generic.List[PSObject]]$tempdata = @() # for detailed test output to return if needed
        $stat   = "PASS" # do not change this
        $except = "WARNING"
        $msg    = "No issues found" # do not change this either
        $query = "SELECT ServerName FROM v_DistributionPointInfo WHERE GroupCount < 1"
        if ($null -ne $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 = $except
            $msg  = "$($res.Count) items found: $($res.ServerName -join ',')"
            $res | Foreach-Object {$tempdata.Add($_.ServerName)}
        }
    }
    catch {
        $stat = 'ERROR'
        $msg = $_.Exception.Message -join ';'
    }
    finally {
        $rt = Get-RunTime -BaseTime $startTime
        Write-Output $([pscustomobject]@{
            TestName    = $TestName
            TestGroup   = $TestGroup
            TestData    = $tempdata
            Description = $Description
            Status      = $stat
            Message     = $msg
            RunTime     = $rt
            Credential  = $(if($ScriptParams.Credential){$($ScriptParams.Credential).UserName} else { $env:USERNAME })
        })
    }
}