src/main/java/dsv/su/apimposter/service/OpenApiService.java

@@ -67,6 +67,7 @@ public class OpenApiService {
                 case PUT    -> item.put(operation);
                 case DELETE -> item.delete(operation);
                 case PATCH  -> item.patch(operation);
+                default     -> throw new IllegalArgumentException("Unsupported HTTP method: " + method);
             }
 
             api.getPaths().addPathItem(path, item);