Add the "Test" cycle analytics section.

app/models/cycle_analytics.rb

@@ -17,6 +17,12 @@ class CycleAnalytics
                      Queries::mr_wip_flag_removed_or_assigned_to_user_other_than_author_time)
   end
 
+  def test
+    calculate_metric(Queries::merge_requests_closing_issues,
+                     Queries::mr_build_started_at,
+                     Queries::mr_build_finished_at)
+  end
+
   def review
     calculate_metric(Queries::merge_requests_closing_issues,
                      Queries::mr_wip_flag_removed_or_assigned_to_user_other_than_author_time,

app/models/cycle_analytics/queries.rb

@@ -40,6 +40,28 @@ class CycleAnalytics
         end
       end
 
+      def mr_build_started_at
+        lambda do |data_point|
+          merge_request = data_point[:merge_request]
+          tip = merge_request.commits.first
+          return unless tip
+
+          pipeline = Ci::Pipeline.find_by_sha(tip.sha)
+          pipeline.started_at if pipeline
+        end
+      end
+
+      def mr_build_finished_at
+        lambda do |data_point|
+          merge_request = data_point[:merge_request]
+          tip = merge_request.commits.first
+          return unless tip
+
+          pipeline = Ci::Pipeline.find_by_sha(tip.sha)
+          pipeline.finished_at if pipeline
+        end
+      end
+
       def mr_deployed_to_any_environment_at
         lambda do |data_point|
           merge_request = data_point[:merge_request]

app/views/projects/cycle_analytics/show.html.haml

@@ -20,6 +20,13 @@
     - else
       = "<Not enough data>"
 
+  %li.list-group-item
+    Test:
+    - if test = @cycle_analytics.test.presence
+      = distance_of_time_in_words test
+    - else
+      = "<Not enough data>"
+
   %li.list-group-item
     Review:
     - if review = @cycle_analytics.review.presence