1 files changed, 130 insertions, 0 deletions
diff --git a/spec/lib/gitlab/analytics/cycle_analytics/aggregated/records_fetcher_spec.rb b/spec/lib/gitlab/analytics/cycle_analytics/aggregated/records_fetcher_spec.rb
new file mode 100644
index 00000000000..045cdb129cb
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+++ b/spec/lib/gitlab/analytics/cycle_analytics/aggregated/records_fetcher_spec.rb
@@ -0,0 +1,130 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Analytics::CycleAnalytics::Aggregated::RecordsFetcher do
+  let_it_be(:project) { create(:project) }
+  let_it_be(:issue_1) { create(:issue, project: project) }
+  let_it_be(:issue_2) { create(:issue, project: project) }
+  let_it_be(:issue_3) { create(:issue, project: project) }
+
+  let_it_be(:stage_event_1) { create(:cycle_analytics_issue_stage_event, issue_id: issue_1.id, start_event_timestamp: 2.years.ago, end_event_timestamp: 1.year.ago) } # duration: 1 year
+  let_it_be(:stage_event_2) { create(:cycle_analytics_issue_stage_event, issue_id: issue_2.id, start_event_timestamp: 5.years.ago, end_event_timestamp: 2.years.ago) } # duration: 3 years
+  let_it_be(:stage_event_3) { create(:cycle_analytics_issue_stage_event, issue_id: issue_3.id, start_event_timestamp: 6.years.ago, end_event_timestamp: 3.months.ago) } # duration: 5+ years
+
+  let_it_be(:stage) { create(:cycle_analytics_project_stage, start_event_identifier: :issue_created, end_event_identifier: :issue_deployed_to_production, project: project) }
+
+  let(:params) { {} }
+
+  subject(:records_fetcher) do
+    described_class.new(stage: stage, query: Analytics::CycleAnalytics::IssueStageEvent.all, params: params)
+  end
+
+  shared_examples 'match returned records' do
+    it 'returns issues in the correct order' do
+      returned_iids = records_fetcher.serialized_records.pluck(:iid).map(&:to_i)
+
+      expect(returned_iids).to eq(expected_issue_ids)
+    end
+  end
+
+  describe '#serialized_records' do
+    describe 'sorting' do
+      context 'when sorting by end event DESC' do
+        let(:expected_issue_ids) { [issue_3.iid, issue_1.iid, issue_2.iid] }
+
+        before do
+          params[:sort] = :end_event
+          params[:direction] = :desc
+        end
+
+        it_behaves_like 'match returned records'
+      end
+
+      context 'when sorting by end event ASC' do
+        let(:expected_issue_ids) { [issue_2.iid, issue_1.iid, issue_3.iid] }
+
+        before do
+          params[:sort] = :end_event
+          params[:direction] = :asc
+        end
+
+        it_behaves_like 'match returned records'
+      end
+
+      context 'when sorting by duration DESC' do
+        let(:expected_issue_ids) { [issue_3.iid, issue_2.iid, issue_1.iid] }
+
+        before do
+          params[:sort] = :duration
+          params[:direction] = :desc
+        end
+
+        it_behaves_like 'match returned records'
+      end
+
+      context 'when sorting by duration ASC' do
+        let(:expected_issue_ids) { [issue_1.iid, issue_2.iid, issue_3.iid] }
+
+        before do
+          params[:sort] = :duration
+          params[:direction] = :asc
+        end
+
+        it_behaves_like 'match returned records'
+      end
+    end
+
+    describe 'pagination' do
+      let(:expected_issue_ids) { [issue_3.iid] }
+
+      before do
+        params[:sort] = :duration
+        params[:direction] = :asc
+        params[:page] = 2
+
+        stub_const('Gitlab::Analytics::CycleAnalytics::Aggregated::RecordsFetcher::MAX_RECORDS', 2)
+      end
+
+      it_behaves_like 'match returned records'
+    end
+
+    context 'when passing a block to serialized_records method' do
+      before do
+        params[:sort] = :duration
+        params[:direction] = :asc
+      end
+
+      it 'yields the underlying stage event scope' do
+        stage_event_records = []
+
+        records_fetcher.serialized_records do |scope|
+          stage_event_records.concat(scope.to_a)
+        end
+
+        expect(stage_event_records.map(&:issue_id)).to eq([issue_1.id, issue_2.id, issue_3.id])
+      end
+    end
+
+    context 'when the issue record no longer exists' do
+      it 'skips non-existing issue records' do
+        create(:cycle_analytics_issue_stage_event, {
+          issue_id: 0, # non-existing id
+          start_event_timestamp: 5.months.ago,
+          end_event_timestamp: 3.months.ago
+        })
+
+        stage_event_count = nil
+
+        records_fetcher.serialized_records do |scope|
+          stage_event_count = scope.to_a.size
+        end
+
+        issue_count = records_fetcher.serialized_records.to_a.size
+
+        expect(stage_event_count).to eq(4)
+        expect(issue_count).to eq(3)
+      end
+    end
+  end
+end