1 files changed, 55 insertions, 0 deletions
diff --git a/lib/gitlab/ci/reports/accessibility_reports_comparer.rb b/lib/gitlab/ci/reports/accessibility_reports_comparer.rb
new file mode 100644
index 00000000000..fa6337166d5
--- /dev/null
+++ b/lib/gitlab/ci/reports/accessibility_reports_comparer.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Reports
+      class AccessibilityReportsComparer
+        include Gitlab::Utils::StrongMemoize
+
+        STATUS_SUCCESS = 'success'
+        STATUS_FAILED = 'failed'
+
+        attr_reader :base_reports, :head_reports
+
+        def initialize(base_reports, head_reports)
+          @base_reports = base_reports || AccessibilityReports.new
+          @head_reports = head_reports
+        end
+
+        def status
+          head_reports.errors_count.positive? ? STATUS_FAILED : STATUS_SUCCESS
+        end
+
+        def existing_errors
+          strong_memoize(:existing_errors) do
+            base_reports.all_errors
+          end
+        end
+
+        def new_errors
+          strong_memoize(:new_errors) do
+            head_reports.all_errors - base_reports.all_errors
+          end
+        end
+
+        def resolved_errors
+          strong_memoize(:resolved_errors) do
+            base_reports.all_errors - head_reports.all_errors
+          end
+        end
+
+        def errors_count
+          head_reports.errors_count
+        end
+
+        def resolved_count
+          resolved_errors.size
+        end
+
+        def total_count
+          existing_errors.size + new_errors.size
+        end
+      end
+    end
+  end
+end