Resolve "Move License Management reports logic for the Merge Request widget to the backend"

ee/app/controllers/ee/projects/merge_requests_controller.rb

@@ -42,6 +42,10 @@ module EE
         render_approvals_json
       end
 
+      def license_management_reports
+        reports_response(merge_request.compare_license_management_reports)
+      end
+
       def metrics_reports
         reports_response(merge_request.compare_metrics_reports)
       end

ee/app/views/projects/merge_requests/show.html.haml

@@ -16,3 +16,4 @@
   window.gl.mrWidgetData.vulnerability_feedback_help_path = '#{help_page_path("user/application_security/index")}';
   window.gl.mrWidgetData.approvals_help_path = '#{help_page_path("user/project/merge_requests/merge_request_approvals")}';
   window.gl.mrWidgetData.visual_review_app_available = '#{@project.feature_available?(:visual_review_app)}' === 'true';
+  window.gl.mrWidgetData.license_management_comparsion_path = '#{license_management_reports_project_merge_request_path(@project, @merge_request) if @project.feature_available?(:license_management)}'

ee/changelogs/unreleased/12020-move-lm-reports-comparision-to-backend.yml

+---
+title: Expose licence management reports comparison
+merge_request: 14723
+author: 
+type: changed

ee/config/routes/project.rb

@@ -68,6 +68,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
       resources :merge_requests, only: [], constraints: { id: /\d+/ } do
         member do
           get :metrics_reports
+          get :license_management_reports
         end
       end
 

ee/spec/controllers/projects/merge_requests_controller_spec.rb

@@ -379,6 +379,91 @@ describe Projects::MergeRequestsController do
     end
   end
 
+  describe 'GET #license_management_reports' do
+    let(:merge_request) { create(:ee_merge_request, :with_license_management_reports, source_project: project, author: create(:user)) }
+    let(:params) do
+      {
+        namespace_id: project.namespace.to_param,
+        project_id: project,
+        id: merge_request.iid
+      }
+    end
+
+    subject { get :license_management_reports, params: params, format: :json }
+
+    before do
+      allow_any_instance_of(::MergeRequest).to receive(:compare_reports)
+        .with(::Ci::CompareLicenseManagementReportsService).and_return(comparison_status)
+    end
+
+    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
+
+        expect(response).to have_gitlab_http_status(:no_content)
+      end
+    end
+
+    context 'when comparison is done' do
+      let(:comparison_status) { { status: :parsed, data: { new_licenses: [], existing_licenses: [], removed_licenses: [] } } }
+
+      it 'does not send polling interval' do
+        expect(::Gitlab::PollingInterval).not_to receive(:set_header)
+
+        subject
+      end
+
+      it 'returns 200 HTTP status' do
+        subject
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to eq({ "new_licenses" => [], "existing_licenses" => [], "removed_licenses" => [] })
+      end
+    end
+
+    context 'when user created corrupted test reports' do
+      let(:comparison_status) { { status: :error, status_reason: 'Failed to parse license management 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
+
+        expect(response).to have_gitlab_http_status(:bad_request)
+        expect(json_response).to eq({ 'status_reason' => 'Failed to parse license management reports' })
+      end
+    end
+
+    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
+
+        expect(response).to have_gitlab_http_status(:internal_server_error)
+        expect(json_response).to eq({ 'status_reason' => 'Unknown error' })
+      end
+    end
+  end
+
   describe 'GET #metrics_reports' do
     let(:merge_request) { create(:ee_merge_request, :with_metrics_reports, source_project: project, author: create(:user)) }