Pointer to string cannot be put into structpb.Value

[tvandinther]

What happened?

cannot compose resources: pipeline step "get-group-objectids" returned a fatal result: cannot convert results data to structpb.Value: proto: invalid type: *string

How can we reproduce it?

I am using the function with the following config:

    - step: get-group-objectids
      functionRef:
        name: function-msgraph
      input:
        apiVersion: msgraph.fn.crossplane.io/v1alpha1
        kind: Input
        queryType: GroupObjectIDs
        groupsRef: spec.allowedGroups
        target: context.allowedGroupObjectIDs
        skipQueryWhenTargetHasData: true

What environment did it happen in?

Function version: v0.2.0

Here are the debug logs for this call:

2025-08-01T10:35:16.697Z    INFO    fn/fn.go:45    Running function    {"tag": "7e7a1038809a831e5e12285d36321d4faa268863c953f572508cc06b0a535ac4"}
2025-08-01T10:35:16.698Z    DEBUG    fn/fn.go:165    Cannot get status from Desired XR or it's empty
2025-08-01T10:35:16.698Z    INFO    fn/fn.go:872    Successfully propagated Desired XR
2025-08-01T10:35:16.698Z    INFO    fn/fn.go:883    Preserved existing context in response
2025-08-01T10:35:16.699Z    INFO    fn/fn.go:966    Resolved GroupsRef to groups    {"groupCount": 2, "groupsRef": "spec.allowedGroups"}
2025-08-01T10:35:17.078Z    INFO    fn/fn.go:211    Query Type:    {"queryType": "GroupObjectIDs"}
2025-08-01T10:35:17.078Z    INFO    fn/fn.go:212    Results:    {"results": "[map[description:<nil> displayName:0xc0003a9830 id:0xc0003a97e0] map[description:<nil> displayName:0xc0001fb1f0 id:0xc0001fb1a0]]"}

I believe the error originates from this line in the codebase: https://github.com/upbound/function-msgraph/blob/main/fn.go#L775

[jonasz-lasut-baloise]

@tvandinther the issue seems to be related to the fact that functions like g.getGroupObjectIDs return a map[string]*string instead of map[string]string. Tests were passing because the query values in tests are mocked and returned correctly as map[string]string.
Fix is implemented in #46