tests/Test-CmClientCoverage.ps1

function Test-CmClientCoverage {
    [CmdletBinding()]
    param (
        [parameter()][string] $TestName = "Test-CmClientCoverage",
        [parameter()][string] $TestGroup = "operation",
        [parameter()][string] $Description = "Confirm AD computers managed by CM",
        [parameter()][hashtable] $ScriptParams
    )
    try {
        [int]$Coverage = Get-CmHealthDefaultValue -KeySet "configmgr:ClientCoverageThresholdPercent" -DataSet $CmHealthConfig
        $Threshold = $Coverage * 0.1
        Write-Verbose "coverage threshold = $Coverage percent"
        $stat = "PASS"
        $msg  = "Coverage meets stated threshold of $Coverage percent"
        [System.Collections.Generic.List[PSObject]]$tempdata = @() # for detailed test output to return if needed
        $adcomps = @(Get-AdsiComputer | Select-Object -ExpandProperty Name)
        $adcount = $adcomps.Count
        Write-Verbose "AD computers = $adcount"
        $query = "select distinct name, clientversion, lasthardwarescan from dbo.v_CombinedDeviceResources where (name not like '%unknown%')"
        if ($ScriptParams.Credential) {
            $cmcomps = @(Invoke-DbaQuery -SqlInstance $ScriptParams.SqlInstance -Database $ScriptParams.Database -Query $query -SqlCredential $ScriptParams.Credential)
        } else {
            $cmcomps = @(Invoke-DbaQuery -SqlInstance $ScriptParams.SqlInstance -Database $ScriptParams.Database -Query $query)
        }
        $cmcount = $cmcomps.Count
        Write-Verbose "CM computers = $cmcount"
        if (($adcount -gt 0) -and ($cmcount -gt 0)) {
            $actual = $($cmcount / $adcount) * 100
            Write-Verbose "actual = $actual"
            if ($actual -lt $Coverage) {
                $stat  = 'WARNING'
                $msg   = "$actual percent coverage is below the minimum threshold of $Coverage percent"
                $tempdata.Add( @{AD_Count = $adcount; CM_Count = $cmcount} )
            } else {
                $msg = "$actual percent coverage is above the minimum threshold of $Coverage percent"
            }
        } else {
            $stat = 'FAIL'
            $msg  = "Unable to query environment data to validate this test"
        }
    }
    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 })
        })
    }
}