Squashed commit of the following:

commit 610c02c305d9fb3c7d271883450a5fee8b0cf16f
Merge: f2088edb260 84f24dce
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 23:01:38 2018 +0900

    Merge branch 'master-ce' into improve-junit-support-be

commit f2088edb26008e5791b7be86fc02fc470c881143
Merge: c67e1d32cac 339f47abec1
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 21:52:10 2018 +0900

    Merge branch 'improve-junit-support-be' of gitlab.com:gitlab-org/gitlab-ce into improve-junit-support-be

commit c67e1d32cac731b895e2f49a24ce0e1726b8196c
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 21:51:39 2018 +0900

    Remove debuggable fixtures

commit 339f47abec1d0ce815e6103a087902d71d8ff5be
Merge: 7a33a9be724 96b748fbcc0
Author: Filipa Lacerda <filipa@gitlab.com>
Date:   Tue Aug 7 11:10:18 2018 +0100

    Merge branch 'improve-junit-support-be' of https://gitlab.com/gitlab-org/gitlab-ce into improve-junit-support-be

    * 'improve-junit-support-be' of https://gitlab.com/gitlab-org/gitlab-ce:
      Add spec for latest
      Add spec for merge request
      Add spec for cache invalidation
      Add spec for pipeline
      Add spec
      Fix specs
      Support corrupted fixtures
      Add  cache key to error message

commit 7a33a9be724dbde79a24cec77658952ff2d2fa6c
Author: Filipa Lacerda <filipa@gitlab.com>
Date:   Tue Aug 7 11:09:56 2018 +0100

    Show resolved failures

commit 96b748fbcc00a98a13aeb78f5d97de9cf25035b6
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 18:50:05 2018 +0900

    Add spec for latest

commit 0e8b024169b4b0ac272331117ac2fa821c4052f7
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 18:24:38 2018 +0900

    Add spec for merge request

commit 8690a699bc98394ad4deebdc91e6690758c5965e
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 18:18:55 2018 +0900

    Add spec for cache invalidation

commit 97678e1612826af409ca8a04b6c0dc830f7b66c6
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 18:01:03 2018 +0900

    Add spec for pipeline

commit 96c2a698af049e4026c68e74b1f41a265464b2b2
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 17:52:21 2018 +0900

    Add spec

commit 67bcbd25a3c13abb78ea43c0411f5aed417b87d0
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 17:39:02 2018 +0900

    Fix specs

commit d7d49def2023f85c07d2718b83f35c8849f65f05
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 13:11:07 2018 +0900

    Support corrupted fixtures

commit d58dbbc17a7d954db22082615f5331c148c1061b
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 13:10:47 2018 +0900

    Add  cache key to error message

commit f6f976216dc36333b5e05e3f0acdfca689350483
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Thu Aug 2 19:07:46 2018 +0900

    bring back debaggable fixtures

commit 48a7800e67a718145c0e88c324c0c1f9619e26a4
Merge: 2822b9e8a36 dd627072
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Aug 7 09:22:22 2018 +0900

    Merge branch 'master-ce' into improve-junit-support-be

commit 2822b9e8a369162d098a72a58803c8494b2343cd
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 22:54:47 2018 +0900

    Move cache invalidation policy to outside of reactive cache

commit b35efb1764ae61bb31dacbf79dbc022dcee3a203
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 22:34:10 2018 +0900

    ADd reactive cache an ability to invalite cache

commit feafee6f8a50f4a32866d8ae768e99766b0b7c73
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 19:25:22 2018 +0900

    Pipeline has test reports if latest builds have any

commit f302dbb73abe03c6c431e7d52d526e28a1586fee
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 19:18:56 2018 +0900

    Invalidate test reports cache if it's outdated

commit 83adaca01a1ee1cd64cac86b6fa3d10e2e4e2b98
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 18:08:06 2018 +0900

    Revert cache invalidation in expire pipeline cache worker

commit ec3af5de4ca34e2e92ad6b97f29733d6c65062bc
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 15:13:47 2018 +0900

    Fix feature spec

commit 0db48805a1ba68763be0504eb57218bde2380e4b
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 14:07:46 2018 +0900

    Change lifetime of test reports cache to 10 minutes

commit 17f7e78bfe2188c349cda1ff90a3ea94d337461e
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 14:07:19 2018 +0900

    Add changelog

commit 89c87585ab7f5333a8139c02b330dd2caf0be31a
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 14:01:20 2018 +0900

    Add feature spec

commit 1120cfd7a9ab06105f2e763c375fab00922b7e0c
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Aug 6 12:55:47 2018 +0900

    Invalidate cache when pipeline status transits. Correct test reports from the latest builds

app/controllers/projects/merge_requests_controller.rb

@@ -102,10 +102,10 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
   def test_reports
     result = @merge_request.compare_test_reports
 
-    Gitlab::PollingInterval.set_header(response, interval: 10_000)
-
     case result[:status]
     when :parsing
+      Gitlab::PollingInterval.set_header(response, interval: 3000)
+
       render json: '', status: :no_content
     when :parsed
       render json: result[:data].to_json, status: :ok

app/models/ci/pipeline.rb

@@ -606,12 +606,12 @@ module Ci
     end
 
     def has_test_reports?
-      complete? && builds.with_test_reports.any?
+      complete? && builds.latest.with_test_reports.any?
     end
 
     def test_reports
       Gitlab::Ci::Reports::TestReports.new.tap do |test_reports|
-        builds.with_test_reports.each do |build|
+        builds.latest.with_test_reports.each do |build|
           build.collect_test_reports!(test_reports)
         end
       end

app/models/concerns/reactive_caching.rb

@@ -42,6 +42,8 @@
 module ReactiveCaching
   extend ActiveSupport::Concern
 
+  InvalidateReactiveCache = Class.new(StandardError)
+
   included do
     class_attribute :reactive_cache_lease_timeout
 
@@ -63,15 +65,19 @@ module ReactiveCaching
     end
 
     def with_reactive_cache(*args, &blk)
-      bootstrap = !within_reactive_cache_lifetime?(*args)
-      Rails.cache.write(alive_reactive_cache_key(*args), true, expires_in: self.class.reactive_cache_lifetime)
+      unless within_reactive_cache_lifetime?(*args)
+        refresh_reactive_cache!(*args)
+        return nil
+      end
 
-      if bootstrap
-        ReactiveCachingWorker.perform_async(self.class, id, *args)
-        nil
-      else
+      keep_alive_reactive_cache!(*args)
+
+      begin
         data = Rails.cache.read(full_reactive_cache_key(*args))
         yield data if data.present?
+      rescue InvalidateReactiveCache
+        refresh_reactive_cache!(*args)
+        nil
       end
     end
 
@@ -96,6 +102,16 @@ module ReactiveCaching
 
     private
 
+    def refresh_reactive_cache!(*args)
+      clear_reactive_cache!(*args)
+      keep_alive_reactive_cache!(*args)
+      ReactiveCachingWorker.perform_async(self.class, id, *args)
+    end
+
+    def keep_alive_reactive_cache!(*args)
+      Rails.cache.write(alive_reactive_cache_key(*args), true, expires_in: self.class.reactive_cache_lifetime)
+    end
+
     def full_reactive_cache_key(*qualifiers)
       prefix = self.class.reactive_cache_key
       prefix = prefix.call(self) if prefix.respond_to?(:call)

app/models/merge_request.rb

@@ -16,8 +16,8 @@ class MergeRequest < ActiveRecord::Base
   include ReactiveCaching
 
   self.reactive_cache_key = ->(model) { [model.project.id, model.iid] }
-  self.reactive_cache_refresh_interval = 1.hour
-  self.reactive_cache_lifetime = 1.hour
+  self.reactive_cache_refresh_interval = 10.minutes
+  self.reactive_cache_lifetime = 10.minutes
 
   ignore_column :locked_at,
                 :ref_fetched,
@@ -1041,16 +1041,21 @@ class MergeRequest < ActiveRecord::Base
       return { status: :error, status_reason: 'This merge request does not have test reports' }
     end
 
-    with_reactive_cache(
-      :compare_test_results,
-      base_pipeline&.iid,
-      actual_head_pipeline.iid) { |data| data } || { status: :parsing }
+    with_reactive_cache(:compare_test_results) do |data|
+      unless Ci::CompareTestReportsService.new(project)
+        .latest?(base_pipeline, actual_head_pipeline, data)
+        raise InvalidateReactiveCache
+      end
+
+      data
+    end || { status: :parsing }
   end
 
   def calculate_reactive_cache(identifier, *args)
     case identifier.to_sym
     when :compare_test_results
-      Ci::CompareTestReportsService.new(project).execute(*args)
+      Ci::CompareTestReportsService.new(project).execute(
+        base_pipeline, actual_head_pipeline)
     else
       raise NotImplementedError, "Unknown identifier: #{identifier}"
     end

app/services/ci/compare_test_reports_service.rb

@@ -2,23 +2,36 @@
 
 module Ci
   class CompareTestReportsService < ::BaseService
-    def execute(base_pipeline_iid, head_pipeline_iid)
-      base_pipeline = project.pipelines.find_by_iid(base_pipeline_iid) if base_pipeline_iid
-      head_pipeline = project.pipelines.find_by_iid(head_pipeline_iid)
-
-      begin
+    def execute(base_pipeline, head_pipeline)
       comparer = Gitlab::Ci::Reports::TestReportsComparer
         .new(base_pipeline&.test_reports, head_pipeline.test_reports)
 
       {
         status: :parsed,
+        key: key(base_pipeline, head_pipeline),
         data: TestReportsComparerSerializer
           .new(project: project)
           .represent(comparer).as_json
       }
     rescue => e
-        { status: :error, status_reason: e.message }
+      {
+        status: :error,
+        key: key(base_pipeline, head_pipeline),
+        status_reason: e.message
+      }
     end
+
+    def latest?(base_pipeline, head_pipeline, data)
+      data&.fetch(:key, nil) == key(base_pipeline, head_pipeline)
+    end
+
+    private
+
+    def key(base_pipeline, head_pipeline)
+      [
+        base_pipeline&.id, base_pipeline&.updated_at,
+        head_pipeline&.id, head_pipeline&.updated_at
+      ]
     end
   end
 end

changelogs/unreleased/improve-junit-support-be.yml

+---
+title: Improve JUnit test reports in merge request widgets
+merge_request: 49966
+author:
+type: fixed

spec/controllers/projects/merge_requests_controller_spec.rb

@@ -597,6 +597,12 @@ describe Projects::MergeRequestsController do
     context 'when comparison is being processed' do
       let(:comparison_status) { { status: :parsing } }
 
+      it 'sends polling interval' do
+        expect(Gitlab::PollingInterval).to receive(:set_header)
+
+        subject
+      end
+
       it 'returns 204 HTTP status' do
         subject
 
@@ -607,6 +613,12 @@ describe Projects::MergeRequestsController do
     context 'when comparison is done' do
       let(:comparison_status) { { status: :parsed, data: { summary: 1 } } }
 
+      it 'does not send polling interval' do
+        expect(Gitlab::PollingInterval).not_to receive(:set_header)
+
+        subject
+      end
+
       it 'returns 200 HTTP status' do
         subject
 
@@ -618,6 +630,12 @@ describe Projects::MergeRequestsController do
     context 'when user created corrupted test reports' do
       let(:comparison_status) { { status: :error, status_reason: 'Failed to parse test reports' } }
 
+      it 'does not send polling interval' do
+        expect(Gitlab::PollingInterval).not_to receive(:set_header)
+
+        subject
+      end
+
       it 'returns 400 HTTP status' do
         subject
 
@@ -629,6 +647,12 @@ describe Projects::MergeRequestsController do
     context 'when something went wrong on our system' do
       let(:comparison_status) { {} }
 
+      it 'does not send polling interval' do
+        expect(Gitlab::PollingInterval).not_to receive(:set_header)
+
+        subject
+      end
+
       it 'returns 500 HTTP status' do
         subject
 

spec/features/merge_request/user_sees_merge_widget_spec.rb

@@ -2,6 +2,7 @@ require 'rails_helper'
 
 describe 'Merge request > User sees merge widget', :js do
   include ProjectForksHelper
+  include TestReportsHelper
 
   let(:project) { create(:project, :repository) }
   let(:project_only_mwps) { create(:project, :repository, only_allow_merge_if_pipeline_succeeds: true) }
@@ -325,4 +326,229 @@ describe 'Merge request > User sees merge widget', :js do
       expect(page).to have_content('This merge request is in the process of being merged')
     end
   end
+
+  context 'when merge request has test reports' do
+    let!(:head_pipeline) do
+      create(:ci_pipeline,
+             :success,
+             project: project,
+             ref: merge_request.source_branch,
+             sha: merge_request.diff_head_sha)
+    end
+
+    let!(:build) { create(:ci_build, :success, pipeline: head_pipeline, project: project) }
+
+    before do
+      merge_request.update!(head_pipeline_id: head_pipeline.id)
+    end
+
+    context 'when result has not been parsed yet' do
+      let!(:job_artifact) { create(:ci_job_artifact, :junit, job: build, project: project) }
+
+      before do
+        visit project_merge_request_path(project, merge_request)
+      end
+
+      it 'shows parsing status' do
+        expect(page).to have_content('Test summary results are being parsed')
+      end
+    end
+
+    context 'when result has already been parsed' do
+      context 'when JUnit xml is correctly formatted' do
+        let!(:job_artifact) { create(:ci_job_artifact, :junit, job: build, project: project) }
+
+        before do
+          allow_any_instance_of(MergeRequest).to receive(:compare_test_reports).and_return(compared_data)
+
+          visit project_merge_request_path(project, merge_request)
+        end
+
+        it 'shows parsed results' do
+          expect(page).to have_content('Test summary contained')
+        end
+      end
+
+      context 'when JUnit xml is corrupted' do
+        let!(:job_artifact) { create(:ci_job_artifact, :junit_with_corrupted_data, job: build, project: project) }
+
+        before do
+          allow_any_instance_of(MergeRequest).to receive(:compare_test_reports).and_return(compared_data)
+
+          visit project_merge_request_path(project, merge_request)
+        end
+
+        it 'shows the error state' do
+          expect(page).to have_content('Test summary failed loading results')
+        end
+      end
+
+      def compared_data
+        Ci::CompareTestReportsService.new(project).execute(nil, head_pipeline)
+      end
+    end
+
+    context 'when test reports have been parsed correctly' do
+      let(:serialized_data) do
+        {
+          status: :parsed,
+          data: TestReportsComparerSerializer
+            .new(project: project)
+            .represent(comparer)
+        }
+      end
+
+      before do
+        allow_any_instance_of(MergeRequest)
+          .to receive(:has_test_reports?).and_return(true)
+        allow_any_instance_of(MergeRequest)
+          .to receive(:compare_test_reports).and_return(serialized_data)
+
+        visit project_merge_request_path(project, merge_request)
+      end
+
+      context 'when a new failures exists' do
+        let(:base_reports) do
+          Gitlab::Ci::Reports::TestReports.new.tap do |reports|
+            reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
+            reports.get_suite('junit').add_test_case(create_test_case_java_success)
+          end
+        end
+
+        let(:head_reports) do
+          Gitlab::Ci::Reports::TestReports.new.tap do |reports|
+            reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
+            reports.get_suite('junit').add_test_case(create_test_case_java_failed)
+          end
+        end
+
+        it 'shows test reports summary which includes the new failure' do
+          within(".mr-section-container") do
+            click_button 'Expand'
+
+            expect(page).to have_content('Test summary contained 1 failed test result out of 2 total tests')
+            within(".js-report-section-container") do
+              expect(page).to have_content('rspec found no changed test results out of 1 total test')
+              expect(page).to have_content('junit found 1 failed test result out of 1 total test')
+              expect(page).to have_content('New')
+              expect(page).to have_content('subtractTest')
+            end
+          end
+        end
+
+        context 'when user clicks the new failure' do
+          it 'shows the test report detail' do
+            within(".mr-section-container") do
+              click_button 'Expand'
+
+              within(".js-report-section-container") do
+                click_button 'subtractTest'
+
+                expect(page).to have_content('6.66')
+                expect(page).to have_content(sample_java_failed_message)
+              end
+            end
+          end
+        end
+      end
+
+      context 'when an existing failure exists' do
+        let(:base_reports) do
+          Gitlab::Ci::Reports::TestReports.new.tap do |reports|
+            reports.get_suite('rspec').add_test_case(create_test_case_rspec_failed)
+            reports.get_suite('junit').add_test_case(create_test_case_java_success)
+          end
+        end
+
+        let(:head_reports) do
+          Gitlab::Ci::Reports::TestReports.new.tap do |reports|
+            reports.get_suite('rspec').add_test_case(create_test_case_rspec_failed)
+            reports.get_suite('junit').add_test_case(create_test_case_java_success)
+          end
+        end
+
+        it 'shows test reports summary which includes the existing failure' do
+          within(".mr-section-container") do
+            click_button 'Expand'
+
+            expect(page).to have_content('Test summary contained 1 failed test result out of 2 total tests')
+            within(".js-report-section-container") do
+              expect(page).to have_content('rspec found 1 failed test result out of 1 total test')
+              expect(page).to have_content('junit found no changed test results out of 1 total test')
+              expect(page).not_to have_content('New')
+              expect(page).to have_content('Test#sum when a is 2 and b is 2 returns summary')
+            end
+          end
+        end
+
+        context 'when user clicks the existing failure' do
+          it 'shows test report detail of it' do
+            within(".mr-section-container") do
+              click_button 'Expand'
+
+              within(".js-report-section-container") do
+                click_button 'Test#sum when a is 2 and b is 2 returns summary'
+
+                expect(page).to have_content('2.22')
+                expect(page).to have_content(sample_rspec_failed_message)
+              end
+            end
+          end
+        end
+      end
+
+      context 'when a resolved failure exists' do
+        let(:base_reports) do
+          Gitlab::Ci::Reports::TestReports.new.tap do |reports|
+            reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
+            reports.get_suite('junit').add_test_case(create_test_case_java_failed)
+          end
+        end
+
+        let(:head_reports) do
+          Gitlab::Ci::Reports::TestReports.new.tap do |reports|
+            reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
+            reports.get_suite('junit').add_test_case(create_test_case_java_resolved)
+          end
+        end
+
+        let(:create_test_case_java_resolved) do
+          create_test_case_java_failed.tap do |test_case|
+            test_case.instance_variable_set("@status", Gitlab::Ci::Reports::TestCase::STATUS_SUCCESS)
+          end
+        end
+
+        it 'shows test reports summary which includes the resolved failure' do
+          within(".mr-section-container") do
+            click_button 'Expand'
+
+            expect(page).to have_content('Test summary contained 1 fixed test result out of 2 total tests')
+            within(".js-report-section-container") do
+              expect(page).to have_content('rspec found no changed test results out of 1 total test')
+              expect(page).to have_content('junit found 1 fixed test result out of 1 total test')
+              expect(page).to have_content('subtractTest')
+            end
+          end
+        end
+
+        context 'when user clicks the resolved failure' do
+          it 'shows test report detail of it' do
+            within(".mr-section-container") do
+              click_button 'Expand'
+
+              within(".js-report-section-container") do
+                click_button 'subtractTest'
+
+                expect(page).to have_content('6.66')
+              end
+            end
+          end
+        end
+      end
+
+      def comparer
+        Gitlab::Ci::Reports::TestReportsComparer.new(base_reports, head_reports)
+      end
+    end
+  end
 end

spec/models/ci/pipeline_spec.rb

@@ -1856,9 +1856,7 @@ describe Ci::Pipeline, :mailer do
 
     context 'when pipeline has builds with test reports' do
       before do
-        create(:ci_build, pipeline: pipeline, project: project).tap do |build|
-          create(:ci_job_artifact, :junit, job: build, project: build.project)
-        end
+        create(:ci_build, :test_reports, pipeline: pipeline, project: project)
       end
 
       context 'when pipeline status is running' do
@@ -1875,6 +1873,22 @@ describe Ci::Pipeline, :mailer do
     end
 
     context 'when pipeline does not have builds with test reports' do
+      before do
+        create(:ci_build, :artifacts, pipeline: pipeline, project: project)
+      end
+
+      let(:pipeline) { create(:ci_pipeline, :success, project: project) }
+
+      it { is_expected.to be_falsey }
+    end
+
+    context 'when retried build has test reports' do
+      before do
+        create(:ci_build, :retried, :test_reports, pipeline: pipeline, project: project)
+      end
+
+      let(:pipeline) { create(:ci_pipeline, :success, project: project) }
+
       it { is_expected.to be_falsey }
     end
   end
@@ -1883,14 +1897,12 @@ describe Ci::Pipeline, :mailer do
     subject { pipeline.test_reports }
 
     context 'when pipeline has multiple builds with test reports' do
-      before do
-        create(:ci_build, :success, name: 'rspec', pipeline: pipeline, project: project).tap do |build|
-          create(:ci_job_artifact, :junit, job: build, project: build.project)
-        end
+      let!(:build_rspec) { create(:ci_build, :success, name: 'rspec', pipeline: pipeline, project: project) }
+      let!(:build_java) { create(:ci_build, :success, name: 'java', pipeline: pipeline, project: project) }
 
-        create(:ci_build, :success, name: 'java', pipeline: pipeline, project: project).tap do |build|
-          create(:ci_job_artifact, :junit_with_ant, job: build, project: build.project)
-        end
+      before do
+        create(:ci_job_artifact, :junit, job: build_rspec, project: project)
+        create(:ci_job_artifact, :junit_with_ant, job: build_java, project: project)
       end
 
       it 'returns test reports with collected data' do
@@ -1898,6 +1910,17 @@ describe Ci::Pipeline, :mailer do
         expect(subject.success_count).to be(5)
         expect(subject.failed_count).to be(2)
       end
+
+      context 'when builds are retried' do
+        let!(:build_rspec) { create(:ci_build, :retried, :success, name: 'rspec', pipeline: pipeline, project: project) }
+        let!(:build_java) { create(:ci_build, :retried, :success, name: 'java', pipeline: pipeline, project: project) }
+
+        it 'does not take retried builds into account' do
+          expect(subject.total_count).to be(0)
+          expect(subject.success_count).to be(0)
+          expect(subject.failed_count).to be(0)
+        end
+      end
     end
 
     context 'when pipeline does not have any builds with test reports' do

spec/models/concerns/reactive_caching_spec.rb

@@ -85,6 +85,14 @@ describe ReactiveCaching, :use_clean_rails_memory_store_caching do
 
         it { is_expected.to be_nil }
       end
+
+      context 'when cache was invalidated' do
+        it 'refreshes cache' do
+          expect(ReactiveCachingWorker).to receive(:perform_async).with(CacheTest, 666)
+
+          instance.with_reactive_cache { raise described_class::InvalidateReactiveCache }
+        end
+      end
     end
   end
 

spec/models/merge_request_spec.rb

@@ -1204,10 +1204,21 @@ describe MergeRequest do
 
         it 'returns status and data' do
           expect_any_instance_of(Ci::CompareTestReportsService)
-            .to receive(:execute).with(base_pipeline.iid, head_pipeline.iid)
+            .to receive(:execute).with(base_pipeline, head_pipeline).and_call_original
 
           subject
         end
+
+        context 'when cached results is not latest' do
+          before do
+            allow_any_instance_of(Ci::CompareTestReportsService)
+              .to receive(:latest?).and_return(false)
+          end
+
+          it 'raises and InvalidateReactiveCache error' do
+            expect { subject }.to raise_error(ReactiveCaching::InvalidateReactiveCache)
+          end
+        end
       end
     end
 

spec/services/ci/compare_test_reports_service_spec.rb

@@ -5,7 +5,7 @@ describe Ci::CompareTestReportsService do
   let(:project) { create(:project, :repository) }
 
   describe '#execute' do
-    subject { service.execute(base_pipeline&.iid, head_pipeline.iid) }
+    subject { service.execute(base_pipeline, head_pipeline) }
 
     context 'when head pipeline has test reports' do
       let!(:base_pipeline) { nil }
@@ -42,4 +42,34 @@ describe Ci::CompareTestReportsService do
       end
     end
   end
+
+  describe '#latest?' do
+    subject { service.latest?(base_pipeline, head_pipeline, data) }
+
+    let!(:base_pipeline) { nil }
+    let!(:head_pipeline) { create(:ci_pipeline, :with_test_reports, project: project) }
+    let!(:key) { service.send(:key, base_pipeline, head_pipeline) }
+
+    context 'when cache key is latest' do
+      let(:data) { { key: key } }
+
+      it { is_expected.to be_truthy }
+    end
+
+    context 'when cache key is outdated' do
+      before do
+        head_pipeline.update_column(:updated_at, 10.minutes.ago)
+      end
+
+      let(:data) { { key: key } }
+
+      it { is_expected.to be_falsy }
+    end
+
+    context 'when cache key is empty' do
+      let(:data) { { key: nil } }
+
+      it { is_expected.to be_falsy }
+    end
+  end
 end