Reverting a merge request | E2E

This is based on the following testcase: gitlab-org/quality/testcases#1745 (closed)

qa/qa/specs/features/browser_ui/3_create/merge_request/revert_spec.rb

+# frozen_string_literal: true
+
+module QA
+  RSpec.describe 'Create' do
+    describe 'Reverting a merged merge request' do
+      let(:project) do
+        Resource::Project.fabricate_via_api! do |project|
+          project.name = 'revert_test_project'
+          project.initialize_with_readme = true
+        end
+      end
+
+      let(:revertable_merge_request) do
+        Resource::MergeRequest.fabricate_via_api! do |merge_request|
+          merge_request.project = project
+          merge_request.target_new_branch = false
+        end
+      end
+
+      before do
+        Flow::Login.sign_in
+      end
+
+      it 'revert a merged merge request with a merge request', testcase: 'https://gitlab.com/gitlab-org/quality/testcases/-/issues/1616' do
+        revertable_merge_request.visit!
+
+        Page::MergeRequest::Show.perform do |merge_request|
+          merge_request.merge!
+          merge_request.revert_with_merge_request!
+        end
+
+        Page::MergeRequest::New.perform do |merge_request|
+          expect(merge_request).to have_content('successfully')
+        end
+      end
+
+      it 'revert a merged merge request without a merge request', testcase: 'https://gitlab.com/gitlab-org/quality/testcases/-/issues/1616' do
+        revertable_merge_request.visit!
+
+        Page::MergeRequest::Show.perform do |merge_request|
+          merge_request.merge!
+          merge_request.revert_without_merge_request!
+        end
+
+        project.visit!
+      end
+    end
+  end
+end