add spec

spec/lib/gitlab/cycle_analytics/events_query_spec.rb → spec/lib/gitlab/cycle_analytics/base_event_fetcher_spec.rb

 require 'spec_helper'
-describe Gitlab::CycleAnalytics::EventsQuery do
-  let(:max_events) { 3 }
+describe Gitlab::CycleAnalytics::BaseEventFetcher do
+  let(:max_events) { 2 }
   let(:project) { create(:project) }
   let(:user) { create(:user, :admin) }
-  let(:options) { { from: 30.days.ago } }
-  let(:issue_event) do
-    Gitlab::CycleAnalytics::IssueEvent.new(project: project, options: options)
-  end
-  subject { described_class.new(project: project, options: options).execute(issue_event) }
+  let(:start_time_attrs) { Issue.arel_table[:created_at] }
+  let(:end_time_attrs) { [Issue::Metrics.arel_table[:first_associated_with_milestone_at]] }
+  let(:options) { { start_time_attrs: start_time_attrs,
+                    end_time_attrs: end_time_attrs,
+                    from: 30.days.ago } }
+  subject do
+    described_class.new(project: project,
+                        stage: :issue,
+                        options: options).fetch
+  end
   before do
     allow_any_instance_of(Gitlab::ReferenceExtractor).to receive(:issues).and_return(Issue.all)
-    stub_const('Gitlab::CycleAnalytics::EventsQuery::MAX_EVENTS', max_events)
-    setup_events(count: 5)
+    allow_any_instance_of(Gitlab::CycleAnalytics::BaseEventFetcher).to receive(:serialize) do |event|
+      event
+    end
+
+    stub_const('Gitlab::CycleAnalytics::BaseEventFetcher::MAX_EVENTS', max_events)
+    setup_events(count: 3)
   end
   it 'limits the rows to the max number' do