Powershell function to add users to AD group from CSV - powershell

Question

I'm building a script to automate AD deployments for customers. We have a prepared list of users and groups in CSV files. The groups are organized in a file with the following format. Keep in mind that I'm using the same CSV file to create the AD groups (which happens in a previous step).
Name,Description,Members
GroupName,GroupDescription,"user1,user2,user3"
The code I'm using to add the users to the groups is below:
$groups = Import-CSV -Path $groupCSVPath
$groups | % { Add-ADGroupMember -Identity $_.Name -Members $_.Members }
This results in an error: Get-ADUser : Cannot find an object with identity: 'user1,user2,user3'.
If I attempt the following, it works:
Add-ADGroupMember -Identity "GroupName" -Members user1,user2,user3
The error appears to reference the Get-ADUser command, which does not accept arrays as inputs. However, the Add-ADGroupMember command does. Why am I getting the Get-ADUser error when using the Add-ADGroupMember command and how can I get it to accept an array of values for the AD Username?

Answer 1

Tricky one. The problem turned out to be that the $_.members parameter is being passed to the Add-ADGroupMember cmdlet as a single string rather than an array of separate values, because of the way Import-CSV works. Get-Help Add-ADGroupMember shows that the members parameter expects an array, not a string.
This should work, I've tested it:
$groups | % { Add-ADGroupMember -Identity $_.Name -Members $_.members.split(',') }