Graphql Mutation for user setting for default seat assignment | Model Selection

Context

For Model selection when no namespace is given because a developer is working in a new repo that is not yet an GitLab project or because they use the various AI capabilities of the GitLab CLI. We are routing the request to a default duo enabled namespace chosen by the user.

Task

Create GQL nodes to mutate the default_duo_add_on_assignment in the user preference table field.

Implementation proposal

For the return types you should use the same Types::GitlabSubscriptions::AddOnPurchaseType. The group or namespace field should be added to it already in #552079 (closed).

 mutation {
  setUserDuoGroup($userId: UserID!, $addOnPurchaseId: GlobalIDType!) {
    nodes {
      addOnPurchase {
        group { # Group type nullable
          id # returns current group
        }
      }
    }
  }

def resolve(**)
  add_on_purchase = authorized_find!(id: add_on_purchase_id)
  assignment = add_on_purchase.assigned_users.by_user(user_to_be_removed).first
  user.user_preferences.update(default_duo_add_on_assignment_id: assigment.id)

  add_on_purchase
end