Limit amount of JUnit tests returned

Currently, we do not cap amount of tests returned to frontend,
thus in some extreme cases we can see a MBs of data stored in Redis.

This adds an upper limit of 100 tests per-suite.

We will continue showing the total counters correctly,
but we will limit amount of tests that will be presented.

4 files changed, 81 insertions, 29 deletions

diff --git a/spec/serializers/test_case_entity_spec.rb b/spec/serializers/test_case_entity_spec.rb
index 986c9feb07b..cc5f086ca4e 100644
--- a/spec/serializers/test_case_entity_spec.rb
+++ b/spec/serializers/test_case_entity_spec.rb
@@ -24,7 +24,7 @@ describe TestCaseEntity do
 
       it 'contains correct test case details' do
         expect(subject[:status]).to eq('failed')
-        expect(subject[:name]).to eq('Test#sum when a is 2 and b is 2 returns summary')
+        expect(subject[:name]).to eq('Test#sum when a is 1 and b is 3 returns summary')
         expect(subject[:classname]).to eq('spec.test_spec')
         expect(subject[:execution_time]).to eq(2.22)
       end
diff --git a/spec/serializers/test_reports_comparer_entity_spec.rb b/spec/serializers/test_reports_comparer_entity_spec.rb
index 59c058fe368..4a951bbbde4 100644
--- a/spec/serializers/test_reports_comparer_entity_spec.rb
+++ b/spec/serializers/test_reports_comparer_entity_spec.rb
@@ -53,13 +53,7 @@ describe TestReportsComparerEntity do
           base_reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
           base_reports.get_suite('junit').add_test_case(create_test_case_java_failed)
           head_reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
-          head_reports.get_suite('junit').add_test_case(create_test_case_java_resolved)
-        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
+          head_reports.get_suite('junit').add_test_case(create_test_case_java_success)
         end
 
         it 'contains correct compared test reports details' do
diff --git a/spec/serializers/test_reports_comparer_serializer_spec.rb b/spec/serializers/test_reports_comparer_serializer_spec.rb
index 9ea86c0dd83..62dc6f486c5 100644
--- a/spec/serializers/test_reports_comparer_serializer_spec.rb
+++ b/spec/serializers/test_reports_comparer_serializer_spec.rb
@@ -44,13 +44,7 @@ describe TestReportsComparerSerializer do
           base_reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
           base_reports.get_suite('junit').add_test_case(create_test_case_java_failed)
           head_reports.get_suite('rspec').add_test_case(create_test_case_rspec_success)
-          head_reports.get_suite('junit').add_test_case(create_test_case_java_resolved)
-        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
+          head_reports.get_suite('junit').add_test_case(create_test_case_java_success)
         end
 
         it 'matches the schema' do
diff --git a/spec/serializers/test_suite_comparer_entity_spec.rb b/spec/serializers/test_suite_comparer_entity_spec.rb
index f61331f53a0..4b2cca2c68c 100644
--- a/spec/serializers/test_suite_comparer_entity_spec.rb
+++ b/spec/serializers/test_suite_comparer_entity_spec.rb
@@ -11,16 +11,10 @@ describe TestSuiteComparerEntity do
   let(:test_case_success) { create_test_case_rspec_success }
   let(:test_case_failed) { create_test_case_rspec_failed }
 
-  let(:test_case_resolved) do
-    create_test_case_rspec_failed.tap do |test_case|
-      test_case.instance_variable_set("@status", Gitlab::Ci::Reports::TestCase::STATUS_SUCCESS)
-    end
-  end
-
   describe '#as_json' do
     subject { entity.as_json }
 
-    context 'when head sutie has a newly failed test case which does not exist in base' do
+    context 'when head suite has a newly failed test case which does not exist in base' do
       before do
         base_suite.add_test_case(test_case_success)
         head_suite.add_test_case(test_case_failed)
@@ -41,7 +35,7 @@ describe TestSuiteComparerEntity do
       end
     end
 
-    context 'when head sutie still has a failed test case which failed in base' do
+    context 'when head suite still has a failed test case which failed in base' do
       before do
         base_suite.add_test_case(test_case_failed)
         head_suite.add_test_case(test_case_failed)
@@ -62,10 +56,10 @@ describe TestSuiteComparerEntity do
       end
     end
 
-    context 'when head sutie has a success test case which failed in base' do
+    context 'when head suite has a success test case which failed in base' do
       before do
         base_suite.add_test_case(test_case_failed)
-        head_suite.add_test_case(test_case_resolved)
+        head_suite.add_test_case(test_case_success)
       end
 
       it 'contains correct compared test suite details' do
@@ -74,13 +68,83 @@ describe TestSuiteComparerEntity do
         expect(subject[:summary]).to include(total: 1, resolved: 1, failed: 0)
         expect(subject[:new_failures]).to be_empty
         subject[:resolved_failures].first.tap do |resolved_failure|
-          expect(resolved_failure[:status]).to eq(test_case_resolved.status)
-          expect(resolved_failure[:name]).to eq(test_case_resolved.name)
-          expect(resolved_failure[:execution_time]).to eq(test_case_resolved.execution_time)
-          expect(resolved_failure[:system_output]).to eq(test_case_resolved.system_output)
+          expect(resolved_failure[:status]).to eq(test_case_success.status)
+          expect(resolved_failure[:name]).to eq(test_case_success.name)
+          expect(resolved_failure[:execution_time]).to eq(test_case_success.execution_time)
+          expect(resolved_failure[:system_output]).to eq(test_case_success.system_output)
         end
         expect(subject[:existing_failures]).to be_empty
       end
     end
+
+    context 'limits amount of tests returned' do
+      before do
+        stub_const('TestSuiteComparerEntity::DEFAULT_MAX_TESTS', 2)
+        stub_const('TestSuiteComparerEntity::DEFAULT_MIN_TESTS', 1)
+      end
+
+      context 'prefers new over existing and resolved' do
+        before do
+          3.times { add_new_failure }
+          3.times { add_existing_failure }
+          3.times { add_resolved_failure }
+        end
+
+        it 'returns 2 new failures, and 1 of resolved and existing' do
+          expect(subject[:summary]).to include(total: 9, resolved: 3, failed: 6)
+          expect(subject[:new_failures].count).to eq(2)
+          expect(subject[:existing_failures].count).to eq(1)
+          expect(subject[:resolved_failures].count).to eq(1)
+        end
+      end
+
+      context 'prefers existing over resolved' do
+        before do
+          3.times { add_existing_failure }
+          3.times { add_resolved_failure }
+        end
+
+        it 'returns 2 existing failures, and 1 resolved' do
+          expect(subject[:summary]).to include(total: 6, resolved: 3, failed: 3)
+          expect(subject[:new_failures].count).to eq(0)
+          expect(subject[:existing_failures].count).to eq(2)
+          expect(subject[:resolved_failures].count).to eq(1)
+        end
+      end
+
+      context 'limits amount of resolved' do
+        before do
+          3.times { add_resolved_failure }
+        end
+
+        it 'returns 2 resolved failures' do
+          expect(subject[:summary]).to include(total: 3, resolved: 3, failed: 0)
+          expect(subject[:new_failures].count).to eq(0)
+          expect(subject[:existing_failures].count).to eq(0)
+          expect(subject[:resolved_failures].count).to eq(2)
+        end
+      end
+
+      private
+
+      def add_new_failure
+        failed_case = create_test_case_rspec_failed(SecureRandom.hex)
+        head_suite.add_test_case(failed_case)
+      end
+
+      def add_existing_failure
+        failed_case = create_test_case_rspec_failed(SecureRandom.hex)
+        base_suite.add_test_case(failed_case)
+        head_suite.add_test_case(failed_case)
+      end
+
+      def add_resolved_failure
+        case_name = SecureRandom.hex
+        failed_case = create_test_case_rspec_failed(case_name)
+        success_case = create_test_case_rspec_success(case_name)
+        base_suite.add_test_case(failed_case)
+        head_suite.add_test_case(success_case)
+      end
+    end
   end
 end