Add integration tests for semantic identifier resolution

Verify that semantic work package identifiers (e.g. "TESTPROJ-1")
are resolved end-to-end through the controller and API layers,
using with_settings/with_flag helpers instead of allow mocks.

spec/controllers/work_packages_controller_spec.rb

@@ -265,6 +265,21 @@ RSpec.describe WorkPackagesController do
     end
   end
 
+  describe "show.html with semantic identifier",
+           with_flag: { semantic_work_package_ids: true },
+           with_settings: { work_packages_identifier: "semantic" } do
+    let(:project) { create(:project, identifier: "TESTPROJ") }
+    let(:call_action) { get("show", params: { id: work_package.display_id.to_s }) }
+
+    requires_permission_in_project do
+      it "resolves the semantic identifier and redirects to the full url" do
+        call_action
+
+        expect(response).to redirect_to("/projects/TESTPROJ/work_packages/#{work_package.display_id}/activity")
+      end
+    end
+  end
+
   describe "show.pdf" do
     let(:call_action) { get("show", params: { format: "pdf", id: work_package.id.to_s }) }
     let(:exporter) { WorkPackage::PDFExport::WorkPackageToPdf }

spec/requests/api/v3/work_packages/show_resource_spec.rb

@@ -217,6 +217,26 @@ RSpec.describe "API v3 Work package resource",
       it_behaves_like "not found response based on login_required",
                       I18n.t("api_v3.errors.not_found.work_package")
     end
+
+    context "with a semantic identifier",
+            with_flag: { semantic_work_package_ids: true },
+            with_settings: { work_packages_identifier: "semantic" } do
+      let(:get_path) { api_v3_paths.work_package work_package.display_id }
+
+      before do
+        get get_path
+      end
+
+      it "resolves the semantic identifier and responds with 200" do
+        expect(last_response).to have_http_status(:ok)
+      end
+
+      it "returns the correct work package" do
+        expect(last_response.body)
+          .to be_json_eql(work_package.id.to_json)
+                .at_path("id")
+      end
+    end
   end
 
   describe "GET /api/v3/work_packages/:id?timestamps=" do