Add empty repo check before running AutoDevOps pipeline

app/controllers/projects/pipelines_settings_controller.rb

@@ -11,9 +11,13 @@ class Projects::PipelinesSettingsController < Projects::ApplicationController
         flash[:notice] = "Pipelines settings for '#{@project.name}' were successfully updated."
 
         if service.run_auto_devops_pipeline?
+          if @project.empty_repo?
+            flash[:warning] = "This repository is currently empty. A new Auto DevOps pipeline will be created after a new file has been pushed to a branch."
+          else
             CreatePipelineWorker.perform_async(project.id, current_user.id, project.default_branch, :web, ignore_skip_ci: true, save_on_errors: false)
             flash[:success] = "A new Auto DevOps pipeline has been created, go to <a href=\"#{project_pipelines_path(@project)}\">Pipelines page</a> for details".html_safe
           end
+        end
 
         redirect_to project_settings_ci_cd_path(@project)
       else

spec/controllers/projects/pipelines_settings_controller_spec.rb

@@ -47,12 +47,40 @@ describe Projects::PipelinesSettingsController do
           expect_any_instance_of(Projects::UpdateService).to receive(:run_auto_devops_pipeline?).and_return(true)
         end
 
+        context 'when the project repository is empty' do
+          before do
+            allow_any_instance_of(Project).to receive(:empty_repo?).and_return(true)
+          end
+
+          it 'sets a warning flash' do
+            expect(subject).to set_flash[:warning]
+          end
+
+          it 'does not queue a CreatePipelineWorker' do
+            expect(CreatePipelineWorker).not_to receive(:perform_async).with(project.id, user.id, project.default_branch, :web, any_args)
+
+            subject
+          end
+        end
+
+        context 'when the project repository is not empty' do
+          before do
+            allow_any_instance_of(Project).to receive(:empty_repo?).and_return(false)
+          end
+
+          it 'sets a success flash' do
+            allow(CreatePipelineWorker).to receive(:perform_async).with(project.id, user.id, project.default_branch, :web, any_args)
+
+            expect(subject).to set_flash[:success]
+          end
+
           it 'queues a CreatePipelineWorker' do
             expect(CreatePipelineWorker).to receive(:perform_async).with(project.id, user.id, project.default_branch, :web, any_args)
 
             subject
           end
         end
+      end
 
       context 'when run_auto_devops_pipeline is not true' do
         before do