Recursively checks for files in a document library that are checked out to a particular user (or checked out at all).

SharePointPnpRecursive.ps1

#Requires -Module SharePointPnPPowerShellOnline

$ErrorActionPreference = 'Stop'
$SPUrl = 'https://yourtenant.sharepoint.com/sites/yourgroup'

# Recursively calls Get-PnpFolderItem for a given Document Library
function Get-PnpFolderItemRecursively($FolderSiteRelativeUrl) {
    
    $Items = @(Get-PnPFolderItem -FolderSiteRelativeUrl $FolderSiteRelativeUrl)
    foreach ($Item in $Items) {
        
        # Strip the Site URL off the item path, because Get-PnpFolderItem wants it
        # to be relative to the site, not an absolute path.
        $ItemPath = $Item.ServerRelativeUrl -replace "^$(([Uri]$Item.Context.Url).AbsolutePath)/",''

        # If this is a directory, recurse into this function.
        # Otherwise, write the item out to the pipeline.
        if ($Item -is [Microsoft.SharePoint.Client.Folder]) {
            Get-PnpFolderItemRecursively $ItemPath
        }
        else {
            Write-Output $Item
        }

    }

}

# Filters the pipeline to only include files that are checked out.
# If -Email parameter is included, then it will be further filtered to
# only files checked out to that user.
function Where-PnpIsCheckedOut([String]$Email) {
    begin {
        $CheckedOutItems = @()
    }
    process {
        # Is this file checked out at all?
        if ($_.CheckOutType -ne 'None') {
            if ($Email) {
                # CheckedOutByUser is not loaded by default.
                # Queue it up for load.
                # Will not actually make a trip to the server until ExecuteQuery later.
                $_.Context.Load($_.CheckedOutByUser)
            }
            $CheckedOutItems += $_
        }
    }
    end {
        foreach ($CheckedOutItem in $CheckedOutItems) {
            if ($Email) {
                # When -Email is specified, we need to load CheckedOutByUser and
                # compare it to the parameter value
                if ($CheckedOutItem.Context.HasPendingRequest) {
                    $CheckedOutItem.Context.ExecuteQuery()
                }
                if ($CheckedOutItem.CheckedOutByUser.Email -match $Email) {
                    Write-Output $CheckedOutItem
                }
            }
            else {
                # When no -Email is specified, all checked out items are returned.
                Write-Output $CheckedOutItem
            }
        }
    }
}


try {

    Connect-PnPOnline -Url $SPUrl -Credentials (Get-Credential)

    Get-PnpFolderItemRecursively 'Shared Documents' |
    Where-PnpIsCheckedOut 'someone@yourtenant.com'

}
catch {

    Write-Error "$_"

}