Cover sending events to rabbitmq

I was mildly annoyed that I couldn't cover the new events to
be sent to rabbitmq, so I did a little research on how to test
bunny. It's not so easy, but good enough to mock

src/api/Gemfile

@@ -133,6 +133,8 @@ group :test do
   gem 'coveralls'
   gem 'minitest-ci'
   gem 'rspec_junit_formatter'
+  # to test rabbitmq support
+  gem 'bunny-mock'
 end
 
 group :development, :test do

src/api/Gemfile.lock

@@ -72,6 +72,8 @@ GEM
       uniform_notifier (~> 1.11)
     bunny (2.12.0)
       amq-protocol (~> 2.3, >= 2.3.0)
+    bunny-mock (1.7.0)
+      bunny (>= 1.7)
     byebug (10.0.2)
     capybara (3.10.1)
       addressable
@@ -457,6 +459,7 @@ DEPENDENCIES
   builder
   bullet
   bunny
+  bunny-mock
   capybara
   capybara_minitest_spec
   chunky_png

src/api/lib/rabbitmq_bus.rb

@@ -1,4 +1,6 @@
 class RabbitmqBus
+  cattr_accessor :connection, :exchange
+
   def self.send_to_bus(channel, data)
     publish("#{Configuration.amqp_namespace}.#{channel}", data)
   rescue => e
@@ -9,21 +11,30 @@ def self.send_to_bus(channel, data)
   def self.publish(event_routing_key, event_payload)
     return unless CONFIG['amqp_options']
     start_connection
-
-    $rabbitmq_exchange.publish(event_payload, routing_key: event_routing_key)
+    wrapped_exchange.publish(event_payload, routing_key: event_routing_key)
   end
 
   # Start one connection, channel and exchange per rails process
   # and reuse them
-  def self.start_connection
-    $rabbitmq_conn ||= Bunny.new(CONFIG['amqp_options'].try(:symbolize_keys))
-    $rabbitmq_conn.start
-    $rabbitmq_channel ||= $rabbitmq_conn.create_channel
-    $rabbitmq_exchange = if CONFIG['amqp_exchange_name']
-      $rabbitmq_channel.exchange(CONFIG['amqp_exchange_name'], CONFIG['amqp_exchange_options'].try(:symbolize_keys) || {})
+  def self.wrapped_exchange
+    return exchange if exchange
+    connection.start
+    rabbitmq_channel = connection.create_channel
+    if CONFIG['amqp_exchange_name']
+      self.exchange = rabbitmq_channel.exchange(CONFIG['amqp_exchange_name'], CONFIG['amqp_exchange_options'].try(:symbolize_keys) || {})
     else
-      $rabbitmq_channel.default_exchange
+      # can't cover due to https://github.com/arempe93/bunny-mock/pull/25
+      #:nocov:
+      self.exchange = rabbitmq_channel.default_exchange
+      #:nocov:
     end
   end
+
+  # this function is skipped in tests by putting a BunnyMock in self.connection
+  def self.start_connection
+    #:nocov:
+    self.connection ||= Bunny.new(CONFIG['amqp_options'].try(:symbolize_keys))
+    #:nocov:
+  end
   private_class_method :start_connection
 end

src/api/spec/lib/rabbitmq_bus_spec.rb

@@ -0,0 +1,19 @@
+require 'rails_helper'
+
+RSpec.describe RabbitmqBus, rabbitmq: '#' do
+  it 'publishes messages' do
+    RabbitmqBus.send_to_bus('metrics', 'hallo')
+    expect_message('opensuse.obs.metrics', 'hallo')
+  end
+
+  context 'with exceptions' do
+    before do
+      allow_any_instance_of(BunnyMock::Queue).to receive(:publish).and_raise(Net::ReadTimeout)
+    end
+
+    it 'disconnects on errors' do
+      RabbitmqBus.send_to_bus('metrics', 'hallo')
+      expect_no_message
+    end
+  end
+end

src/api/spec/models/update_notification_events_spec.rb

@@ -0,0 +1,49 @@
+require 'rails_helper'
+
+RSpec.describe UpdateNotificationEvents, type: :model do
+  let!(:admin) { create(:admin_user, login: 'Admin') }
+  let(:notifications) do
+    <<-RESPONSE
+        <notifications next="3">
+          <notification type="SRCSRV_CREATE_PROJECT" time="1539445101">
+            <data key="project">project_1</data>
+            <data key="sender">_nobody_</data>
+          </notification>
+          <notification type="SRCSRV_CREATE_PACKAGE" time="1539445101">
+            <data key="package">multibuild</data>
+            <data key="project">project_1</data>
+            <data key="sender">_nobody_</data>
+          </notification>
+        </notifications>
+    RESPONSE
+  end
+
+  before do
+    url = CONFIG['source_url'] + '/lastnotifications?block=1&start=1'
+    stub_request(:get, url).and_return(body: notifications)
+  end
+
+  it 'fetches events' do
+    UpdateNotificationEvents.new.perform
+    expect(BackendInfo.lastnotification_nr).to eq(3)
+  end
+
+  context 'with configured amqp', rabbitmq: '#' do
+    it 'sends events' do
+      # not interested in setup messages
+      empty_message_queue
+
+      UpdateNotificationEvents.new.perform
+
+      # SRCSRV_CREATE_PROJECT
+      expect_message('opensuse.obs.project.create', '{"project":"project_1","sender":"_nobody_"}')
+      expect_message('opensuse.obs.metrics', 'project.create,home=false value=1')
+
+      # SRCSRV_CREATE_PACKAGE
+      expect_message('opensuse.obs.package.create', '{"project":"project_1","package":"multibuild","sender":"_nobody_"}')
+      expect_message('opensuse.obs.metrics', 'package.create,home=false value=1')
+
+      expect_no_message
+    end
+  end
+end

src/api/spec/rails_helper.rb

@@ -80,3 +80,6 @@
 
 # silence migration tests
 require 'support/migration'
+
+# support rabbitmq
+require 'support/rabbitmq'

src/api/spec/support/rabbitmq.rb

@@ -0,0 +1,34 @@
+module RabbitMQHelpers
+  cattr_accessor :test_queue
+
+  def empty_message_queue
+    test_queue.purge
+  end
+
+  def expect_no_message
+    expect(test_queue.message_count).to eq(0)
+  end
+
+  def expect_message(routing_key, message)
+    expect(test_queue.all.shift).to include(message: message, options: { routing_key: routing_key, exchange: 'pubsub' })
+  end
+end
+
+RSpec.configure do |config|
+  config.before do |example|
+    if example.metadata[:rabbitmq]
+      config.include RabbitMQHelpers
+      # define config - not taken into account though due to mocking
+      stub_const('CONFIG', CONFIG.merge('amqp_options' => { dummy: 1 }, 'amqp_exchange_name' => 'pubsub', 'amqp_exchange_options' => { type: :topic }))
+
+      connection = BunnyMock.new
+      RabbitmqBus.connection = connection
+      # setup exchange
+      RabbitmqBus.exchange = nil
+      RabbitmqBus.wrapped_exchange
+
+      RabbitMQHelpers.test_queue = connection.channel.queue('test')
+      RabbitMQHelpers.test_queue.bind('pubsub', routing_key: example.metadata[:rabbitmq])
+    end
+  end
+end