Add update_v2_subscription endpoint in billing client

Author: Stanislav Kolotinskiy

lib/travis/api/v3/billing_client.rb

@@ -94,6 +94,11 @@ def create_v2_subscription(subscription_data)
       handle_v2_subscription_response(response)
     end
 
+    def update_v2_subscription(subscription_id, plan_data)
+      response = connection.patch("/v2/subscriptions/#{subscription_id}/plan", plan_data)
+      handle_v2_subscription_response(response)
+    end
+
     def cancel_subscription(id, reason_data)
       response = connection.post("/subscriptions/#{id}/cancel", reason_data)
       handle_subscription_response(response)

spec/v3/billing_client_spec.rb

@@ -232,6 +232,20 @@
     end
   end
 
+  describe '#update_v2_subscription' do
+    let(:plan_data) { { 'plan' => 'enterprise_tier_plan' } }
+    subject { billing.update_v2_subscription(subscription_id, plan_data) }
+
+    it 'requests the update' do
+      stubbed_request = stub_billing_request(:patch, "/v2/subscriptions/#{subscription_id}/plan", auth_key: auth_key, user_id: user_id)
+        .with(body: JSON.dump(plan_data))
+        .to_return(status: 204)
+
+      expect { subject }.to_not raise_error
+      expect(stubbed_request).to have_been_made
+    end
+  end
+
   describe '#pay' do
     subject { billing.pay(subscription_id) }