Cache merged and closed events data in merge_request_metrics table

2 files changed, 74 insertions, 13 deletions

diff --git a/spec/serializers/event_entity_spec.rb b/spec/serializers/event_entity_spec.rb
deleted file mode 100644
index bb54597c967..00000000000
--- a/spec/serializers/event_entity_spec.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-require 'spec_helper'
-
-describe EventEntity do
-  subject { described_class.represent(create(:event)).as_json }
-
-  it 'exposes author' do
-    expect(subject).to include(:author)
-  end
-
-  it 'exposes core elements of event' do
-    expect(subject).to include(:updated_at)
-  end
-end
diff --git a/spec/serializers/merge_request_widget_entity_spec.rb b/spec/serializers/merge_request_widget_entity_spec.rb
index a5924a8589c..9bbe815c115 100644
--- a/spec/serializers/merge_request_widget_entity_spec.rb
+++ b/spec/serializers/merge_request_widget_entity_spec.rb
@@ -35,6 +35,80 @@ describe MergeRequestWidgetEntity do
     end
   end
 
+  describe 'metrics' do
+    context 'when metrics record exists with merged data' do
+      before do
+        resource.mark_as_merged!
+        resource.metrics.update!(merged_by: user)
+      end
+
+      it 'matches merge request metrics schema' do
+        expect(subject[:metrics].with_indifferent_access)
+          .to match_schema('entities/merge_request_metrics')
+      end
+
+      it 'returns values from metrics record' do
+        expect(subject.dig(:metrics, :merged_by, :id))
+          .to eq(resource.metrics.merged_by_id)
+      end
+    end
+
+    context 'when metrics record exists with closed data' do
+      before do
+        resource.close!
+        resource.metrics.update!(latest_closed_by: user)
+      end
+
+      it 'matches merge request metrics schema' do
+        expect(subject[:metrics].with_indifferent_access)
+          .to match_schema('entities/merge_request_metrics')
+      end
+
+      it 'returns values from metrics record' do
+        expect(subject.dig(:metrics, :closed_by, :id))
+          .to eq(resource.metrics.latest_closed_by_id)
+      end
+    end
+
+    context 'when metrics does not exists' do
+      before do
+        resource.metrics.destroy!
+        resource.reload
+      end
+
+      context 'when events exists' do
+        let!(:closed_event) { create(:event, :closed, project: project, target: resource) }
+        let!(:merge_event) { create(:event, :merged, project: project, target: resource) }
+
+        it 'matches merge request metrics schema' do
+          expect(subject[:metrics].with_indifferent_access)
+            .to match_schema('entities/merge_request_metrics')
+        end
+
+        it 'returns values from events record' do
+          expect(subject.dig(:metrics, :merged_by, :id))
+            .to eq(merge_event.author_id)
+
+          expect(subject.dig(:metrics, :closed_by, :id))
+            .to eq(closed_event.author_id)
+
+          expect(subject.dig(:metrics, :merged_at).to_s)
+            .to eq(merge_event.updated_at.to_s)
+
+          expect(subject.dig(:metrics, :closed_at).to_s)
+            .to eq(closed_event.updated_at.to_s)
+        end
+      end
+
+      context 'when events does not exists' do
+        it 'matches merge request metrics schema' do
+          expect(subject[:metrics].with_indifferent_access)
+            .to match_schema('entities/merge_request_metrics')
+        end
+      end
+    end
+  end
+
   it 'has email_patches_path' do
     expect(subject[:email_patches_path])
       .to eq("/#{resource.project.full_path}/merge_requests/#{resource.iid}.patch")