5 files changed, 220 insertions, 0 deletions
diff --git a/lib/gitlab/ci/reports/test_case.rb b/lib/gitlab/ci/reports/test_case.rb
new file mode 100644
index 00000000000..b4d08ed257f
--- /dev/null
+++ b/lib/gitlab/ci/reports/test_case.rb
@@ -0,0 +1,32 @@
+module Gitlab
+  module Ci
+    module Reports
+      class TestCase
+        STATUS_SUCCESS = 'success'.freeze
+        STATUS_FAILED = 'failed'.freeze
+        STATUS_SKIPPED = 'skipped'.freeze
+        STATUS_ERROR = 'error'.freeze
+        STATUS_TYPES = [STATUS_SUCCESS, STATUS_FAILED, STATUS_SKIPPED, STATUS_ERROR].freeze
+
+        attr_reader :name, :classname, :execution_time, :status, :file, :system_output, :stack_trace, :key
+
+        def initialize(name:, classname:, execution_time:, status:, file: nil, system_output: nil, stack_trace: nil)
+          @name = name
+          @classname = classname
+          @file = file
+          @execution_time = execution_time.to_f
+          @status = status
+          @system_output = system_output
+          @stack_trace = stack_trace
+          @key = sanitize_key_name("#{classname}_#{name}")
+        end
+
+        private
+
+        def sanitize_key_name(key)
+          key.gsub(/[^0-9A-Za-z]/, '-')
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/reports/test_reports.rb b/lib/gitlab/ci/reports/test_reports.rb
new file mode 100644
index 00000000000..c6e732e68eb
--- /dev/null
+++ b/lib/gitlab/ci/reports/test_reports.rb
@@ -0,0 +1,39 @@
+module Gitlab
+  module Ci
+    module Reports
+      class TestReports
+        attr_reader :test_suites
+
+        def initialize
+          @test_suites = {}
+        end
+
+        def get_suite(suite_name)
+          test_suites[suite_name] ||= TestSuite.new(suite_name)
+        end
+
+        def total_time
+          test_suites.values.sum(&:total_time)
+        end
+
+        def total_count
+          test_suites.values.sum(&:total_count)
+        end
+
+        def total_status
+          if failed_count > 0 || error_count > 0
+            TestCase::STATUS_FAILED
+          else
+            TestCase::STATUS_SUCCESS
+          end
+        end
+
+        TestCase::STATUS_TYPES.each do |status_type|
+          define_method("#{status_type}_count") do
+            test_suites.values.sum { |suite| suite.public_send("#{status_type}_count") } # rubocop:disable GitlabSecurity/PublicSend
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/reports/test_reports_comparer.rb b/lib/gitlab/ci/reports/test_reports_comparer.rb
new file mode 100644
index 00000000000..c0943f5a51a
--- /dev/null
+++ b/lib/gitlab/ci/reports/test_reports_comparer.rb
@@ -0,0 +1,38 @@
+module Gitlab
+  module Ci
+    module Reports
+      class TestReportsComparer
+        include Gitlab::Utils::StrongMemoize
+
+        attr_reader :base_reports, :head_reports
+
+        def initialize(base_reports, head_reports)
+          @base_reports = base_reports || TestReports.new
+          @head_reports = head_reports
+        end
+
+        def suite_comparers
+          strong_memoize(:suite_comparers) do
+            head_reports.test_suites.map do |name, test_suite|
+              TestSuiteComparer.new(name, base_reports.get_suite(name), test_suite)
+            end
+          end
+        end
+
+        def total_status
+          if suite_comparers.any? { |suite| suite.total_status == TestCase::STATUS_FAILED }
+            TestCase::STATUS_FAILED
+          else
+            TestCase::STATUS_SUCCESS
+          end
+        end
+
+        %w(total_count resolved_count failed_count).each do |method|
+          define_method(method) do
+            suite_comparers.sum { |suite| suite.public_send(method) } # rubocop:disable GitlabSecurity/PublicSend
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/reports/test_suite.rb b/lib/gitlab/ci/reports/test_suite.rb
new file mode 100644
index 00000000000..b722d0ba735
--- /dev/null
+++ b/lib/gitlab/ci/reports/test_suite.rb
@@ -0,0 +1,54 @@
+module Gitlab
+  module Ci
+    module Reports
+      class TestSuite
+        attr_reader :name
+        attr_reader :test_cases
+        attr_reader :total_time
+
+        def initialize(name = nil)
+          @name = name
+          @test_cases = {}
+          @total_time = 0.0
+          @duplicate_cases = []
+        end
+
+        def add_test_case(test_case)
+          @duplicate_cases << test_case if existing_key?(test_case)
+
+          @test_cases[test_case.status] ||= {}
+          @test_cases[test_case.status][test_case.key] = test_case
+          @total_time += test_case.execution_time
+        end
+
+        def total_count
+          test_cases.values.sum(&:count)
+        end
+
+        def total_status
+          if failed_count > 0 || error_count > 0
+            TestCase::STATUS_FAILED
+          else
+            TestCase::STATUS_SUCCESS
+          end
+        end
+
+        TestCase::STATUS_TYPES.each do |status_type|
+          define_method("#{status_type}") do
+            test_cases[status_type] || {}
+          end
+
+          define_method("#{status_type}_count") do
+            test_cases[status_type]&.length.to_i
+          end
+        end
+
+        private
+
+        def existing_key?(test_case)
+          @test_cases[test_case.status]&.key?(test_case.key)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/reports/test_suite_comparer.rb b/lib/gitlab/ci/reports/test_suite_comparer.rb
new file mode 100644
index 00000000000..642aa593092
--- /dev/null
+++ b/lib/gitlab/ci/reports/test_suite_comparer.rb
@@ -0,0 +1,57 @@
+module Gitlab
+  module Ci
+    module Reports
+      class TestSuiteComparer
+        include Gitlab::Utils::StrongMemoize
+
+        attr_reader :name, :base_suite, :head_suite
+
+        def initialize(name, base_suite, head_suite)
+          @name = name
+          @base_suite = base_suite || TestSuite.new
+          @head_suite = head_suite
+        end
+
+        def new_failures
+          strong_memoize(:new_failures) do
+            head_suite.failed.reject do |key, _|
+              base_suite.failed.include?(key)
+            end.values
+          end
+        end
+
+        def existing_failures
+          strong_memoize(:existing_failures) do
+            head_suite.failed.select do |key, _|
+              base_suite.failed.include?(key)
+            end.values
+          end
+        end
+
+        def resolved_failures
+          strong_memoize(:resolved_failures) do
+            head_suite.success.select do |key, _|
+              base_suite.failed.include?(key)
+            end.values
+          end
+        end
+
+        def total_count
+          head_suite.total_count
+        end
+
+        def total_status
+          head_suite.total_status
+        end
+
+        def resolved_count
+          resolved_failures.count
+        end
+
+        def failed_count
+          new_failures.count + existing_failures.count
+        end
+      end
+    end
+  end
+end