Expose `plan` and `trial` in the `/users` endpoint

`plan` is hooked up to the models but trial is not yet.

changelogs/unreleased/198391-add-user-plan-and-trial-status-to-api.yml

+---
+title: Expose `plan` and `trial` to `/users/:id` endpoint
+merge_request: 25151
+author:
+type: added

doc/api/users.md

@@ -304,10 +304,14 @@ Example Responses:
   "external": false,
   "private_profile": false,
   "current_sign_in_ip": "196.165.1.102",
-  "last_sign_in_ip": "172.127.2.22"
+  "last_sign_in_ip": "172.127.2.22",
+  "plan": "gold",
+  "trial": true
 }
 ```
 
+NOTE: **Note:** The `plan` and `trial` parameters are only available on GitLab Enterprise Edition.
+
 Users on GitLab [Starter, Bronze, or higher](https://about.gitlab.com/pricing/) will also see
 the `shared_runners_minutes_limit`, `extra_shared_runners_minutes_limit`, and `note` parameters.
 

ee/lib/ee/api/entities.rb

@@ -539,6 +539,20 @@ module EE
           end
         end
       end
+
+      module UserDetailsWithAdmin
+        extend ActiveSupport::Concern
+
+        prepended do
+          expose :plan do |user|
+            user.namespace.try(:gitlab_subscription)&.plan_name
+          end
+
+          expose :trial do |user|
+            user.namespace.try(:trial?)
+          end
+        end
+      end
     end
   end
 end

ee/spec/requests/api/users_spec.rb

@@ -276,4 +276,60 @@ describe API::Users do
       end
     end
   end
+
+  describe 'GET /user/:id' do
+    context 'when authenticated' do
+      context 'as an admin' do
+        context 'and user has a plan' do
+          let!(:subscription) { create(:gitlab_subscription, :gold, namespace: user.namespace) }
+
+          context 'and user is not a trial user' do
+            it 'contains plan and trial' do
+              get api("/users/#{user.id}", admin)
+
+              expect(json_response).to include('plan' => 'gold', 'trial' => false)
+            end
+          end
+
+          context 'and user is a trial user' do
+            before do
+              subscription.update!(trial: true)
+            end
+
+            it 'contains plan and trial' do
+              get api("/users/#{user.id}", admin)
+
+              expect(json_response).to include('plan' => 'gold', 'trial' => true)
+            end
+          end
+        end
+
+        context 'and user has no plan' do
+          it 'returns `nil` for both plan and trial' do
+            get api("/users/#{user.id}", admin)
+
+            expect(json_response).to include('plan' => nil, 'trial' => nil)
+          end
+        end
+      end
+
+      context 'as a user' do
+        it 'does not contain plan and trial info' do
+          get api("/users/#{user.id}", user)
+
+          expect(json_response).not_to have_key('plan')
+          expect(json_response).not_to have_key('trial')
+        end
+      end
+    end
+
+    context 'when not authenticated' do
+      it 'does not contain plan and trial info' do
+        get api("/users/#{user.id}")
+
+        expect(json_response).not_to have_key('plan')
+        expect(json_response).not_to have_key('trial')
+      end
+    end
+  end
 end

lib/api/entities/user_details_with_admin.rb

@@ -9,3 +9,5 @@ module API
     end
   end
 end
+
+API::Entities::UserDetailsWithAdmin.prepend_if_ee('EE::API::Entities::UserDetailsWithAdmin')

spec/requests/api/users_spec.rb

@@ -330,6 +330,14 @@ describe API::Users, :do_not_mock_admin_mode do
       expect(json_response.keys).not_to include 'last_sign_in_ip'
     end
 
+    it "does not contain plan or trial data" do
+      get api("/users/#{user.id}", user)
+
+      expect(response).to match_response_schema('public_api/v4/user/basic')
+      expect(json_response.keys).not_to include 'plan'
+      expect(json_response.keys).not_to include 'trial'
+    end
+
     context 'when job title is present' do
       let(:job_title) { 'Fullstack Engineer' }
 
@@ -367,6 +375,22 @@ describe API::Users, :do_not_mock_admin_mode do
         expect(json_response['highest_role']).to be(0)
       end
 
+      if Gitlab.ee?
+        it 'does not include values for plan or trial' do
+          get api("/users/#{user.id}", admin)
+
+          expect(response).to match_response_schema('public_api/v4/user/basic')
+        end
+      else
+        it 'does not include plan or trial data' do
+          get api("/users/#{user.id}", admin)
+
+          expect(response).to match_response_schema('public_api/v4/user/basic')
+          expect(json_response.keys).not_to include 'plan'
+          expect(json_response.keys).not_to include 'trial'
+        end
+      end
+
       context 'when user has not logged in' do
         it 'does not include the sign in IPs' do
           get api("/users/#{user.id}", admin)