Extend the delete method so it has an option for safety

No change to the default behaviour

pyiron_workflow/files.py

@@ -43,8 +43,9 @@ def __init__(self, directory):
     def create(self):
         self.path.mkdir(parents=True, exist_ok=True)
 
-    def delete(self):
-        delete_files_and_directories_recursively(self.path)
+    def delete(self, only_if_empty: bool = False):
+        if self.is_empty or not only_if_empty:
+            delete_files_and_directories_recursively(self.path)
 
     def list_content(self):
         return categorize_folder_items(self.path)

tests/unit/test_files.py

@@ -50,6 +50,24 @@ def test_is_empty(self):
         self.directory.write(file_name="test.txt", content="something")
         self.assertFalse(self.directory.is_empty)
 
+    def test_delete(self):
+        self.assertTrue(
+            Path("test").exists() and Path("test").is_dir(),
+            msg="Sanity check on initial state"
+        )
+        self.directory.write(file_name="test.txt", content="something")
+        self.directory.delete(only_if_empty=True)
+        self.assertFalse(
+            self.directory.is_empty,
+            msg="Flag argument on delete should have prevented removal"
+        )
+        self.directory.delete()
+        self.assertFalse(
+            Path("test").exists(),
+            msg="Delete should remove the entire directory"
+        )
+        self.directory = DirectoryObject("test")  # Rebuild it so the tearDown works
+
 
 if __name__ == '__main__':
     unittest.main()