`UserGroup undefined` error when activating GroupInvitation.

[xanderjakeq]

(Assuming #76 is resolved)

I got UserGroup undefined errors when activating a GroupInvitation.
The line below would be the problem.

https://github.com/blockstack/radiks/blob/0d97225e9b828d5348960236fdd4b83c266cbdaa/src/models/group-membership.ts#L91

The code above is trying to get the UserGroup of a GroupMembership model.

https://github.com/blockstack/radiks/blob/0d97225e9b828d5348960236fdd4b83c266cbdaa/src/models/group-membership.ts#L40

When the GroupMembership's UserGroup is deleted, it makes sense that the error would occur.

Should radiks handle this situation or should the app dev? @hstove

[friedger]

@xanderjakeq Do you get the error only when the group was deleted? Could you please add a simple test?

I think radiks should handle this in a meaningful way for the developer.

[xanderjakeq]

Here's some steps to replicate:

1. user1 creates userGroup1.
2. user1 invites user2 to userGroup1
3. user2 activates Invitation to userGroup1
4. user1 deletes userGroup1
5. user1 creates userGroup2.
6. user1 invites user2 to userGroup2
7. user2 activates Invitation to userGroup2
8. then should get a UserGroup undefined error

[friedger]

Ideally all memberships are deleted when deleting a group. At least fetching a usergroup from a membership should return {} if the group does not exist anymore.