Supporting casting or object type filtering for groups membership

[will-bartlett]

I'd like .NET Graph SDK to support the full features of Graph (or, alternatively, I can't find the docs for what I need). I'd like to make a request to:

https://graph.microsoft.com/v1.0/groups/{groupId}/members/microsoft.graph.group

OR

https://graph.microsoft.com/v1.0/groups/{groupId}/members?$filter=isof('microsoft.graph.group')

That is - I'd like to look at group membership, but filtered to only groups (ignoring users). The "isof" selector here is supported by the client library, but not the server. And, the casting ("/microsoft.graph.group") appears to be supported on the server but not in the client library. For this request, Graph Explorer shows sample code for .NET that corresponds to:

https://graph.microsoft.com/v1.0/groups/{groupId}/members

I experimented a little with the SDK based on some of the code in depot and eventually wrote:

            var originalUrl = GraphClient
                .Groups[groupId]
                .Members
                .RequestUrl;

            Type t = typeof(Group);

            return new GroupMembersCollectionWithReferencesRequestBuilder($"{originalUrl}/{t.FullName}", GraphClient)
                .Request();

This way, the SDK would make the request, but deserialization was problematic. Because the Graph API does not return an @odata.type when it's specified by the caller, the .NET Graph SDK deserialized the response objects as if they were generic DirectoryObjects rather than Groups, which is not productive.

Describe the solution you'd like
I'd like to be able to write something like:

GraphClient
    .Groups[groupId]
    .Members
    .Cast<Group>()
    .Request();

Describe alternatives you've considered
I'll probably just not filter my results (extra bandwidth / latency, but the feature works).
AB#6678

[MIchaelMainer]

This feature request needs to be implemented similar to what we have in Java.

[andrueastman]

This is tracked via microsoftgraph/MSGraph-SDK-Code-Generator#239

[maisarissi]

This will be addressed in Kiota via microsoft/kiota#648

[andrueastman]

With the latest V5 preview version, this should now be possible to do with code similar to this.

var usersInGroup = await graphServiceClient.Groups["group-id"].Members.User.GetAsync();

More information is also available in the upgrade guide here.