Compare-SearchResultsCountToItemCount.ps1

#requires -modules "PnP.PowerShell"

# requires SharePoint > application > sites.fullcontrol.all permissions

$sites = "https://m365cpi68930152.sharepoint.com/sites/security-policies1",
         "https://m365cpi68930152.sharepoint.com/sites/security-policies2"

$timestamp = Get-Date -Format FileDateTime 

foreach( $site in $sites )
{
    Write-Host "[$(Get-Date)] - Testing Site: $site"

    Connect-PnPOnline -Url        $site `
                      -ClientId   $env:CDX_CLIENTID `
                      -Thumbprint $env:CDX_THUMBPRINT `
                      -Tenant     $env:CDX_TENANTID

    $context = Get-PNPContext

    $hostname = [System.Uri]::new( $context.Url ).Host

    $lists = Get-PnpList -Includes RootFolder.ServerRelativeUrl | Where-Object { $_.Hidden -eq $false -and $_.BaseType -eq "DocumentLibrary" }

    $searchResults = foreach( $list in $lists )
    {
        if( $list.ItemCount -gt 0 )
        {
            $path = "`"https://$hostname$($list.RootFolder.ServerRelativeUrl)`""

            $results = Invoke-PnPSearchQuery -Query "path:$path" -TrimDuplicates $true

            if( $results.TotalRows -gt 0 )
            {
                # one or more items in doc lib are indexed

                [PSCustomObject] @{
                    Site               = $context.Url
                    List               = $list.Title
                    ListItemCount      = $list.ItemCount
                    SearchResultsCount = $results.TotalRows
                }
            }
        }
    }

    if( $searchResults )
    {
        $searchResults | Export-Csv -Path "C:\_temp\SeachResults_$timestamp.csv" -Append -NoTypeInformation
    }
}