Removes seat count defaults to avoid data loss

ee/lib/ee/api/namespaces.rb

@@ -36,8 +36,8 @@ module EE
         resource :namespaces, requirements: ::API::API::NAMESPACE_OR_PROJECT_REQUIREMENTS do
           helpers do
             params :gitlab_subscription_optional_attributes do
-              optional :seats, type: Integer, default: 0, desc: 'The number of seats purchased'
-              optional :max_seats_used, type: Integer, default: 0, desc: 'The max number of active users detected in the last month'
+              optional :seats, type: Integer, desc: 'The number of seats purchased'
+              optional :max_seats_used, type: Integer, desc: 'The max number of active users detected in the last month'
               optional :plan_code, type: String, desc: 'The code of the purchased plan'
               optional :end_date, type: Date, desc: 'The date when subscription expires'
               optional :auto_renew, type: Grape::API::Boolean, desc: 'Whether the subscription auto renews'

ee/spec/requests/api/namespaces_spec.rb

@@ -342,14 +342,27 @@ describe API::Namespaces do
 
           expect(response).to have_gitlab_http_status(:ok)
           expect(gitlab_subscription.reload.seats).to eq(150)
+          expect(gitlab_subscription.max_seats_used).to eq(0)
           expect(gitlab_subscription.plan_name).to eq('silver')
           expect(gitlab_subscription.plan_title).to eq('Silver')
         end
 
-        it 'is sucessful using full_path when namespace path contains dots' do
-          put api("/namespaces/#{namespace.full_path}/gitlab_subscription", admin), params: params
+        it 'is successful using full_path when namespace path contains dots' do
+          do_put(namespace.id, admin, params)
+
+          expect(response).to have_gitlab_http_status(:ok)
+        end
+
+        it 'does not clear out existing data because of defaults' do
+          gitlab_subscription.update!(seats: 20, max_seats_used: 42)
+
+          do_put(namespace.id, admin, params.except(:seats))
 
           expect(response).to have_gitlab_http_status(:ok)
+          expect(gitlab_subscription.reload).to have_attributes(
+            seats: 20,
+            max_seats_used: 42
+          )
         end
       end
     end