I can add new columns

tests/controls/test_datagrid_columns_manager.py

@@ -36,7 +36,7 @@ class MockDataGrid(MultipleInstance):
   
   def get_table_name(self):
     return "mock_table"
-
+  
   def get_formula_engine(self):
     return None
 
@@ -163,7 +163,6 @@ class TestDataGridColumnsManagerBehaviour:
   def test_i_can_update_column_title(self, columns_manager):
     """Test updating a column's title via client_response."""
     columns_manager.save_column_details("name", {"title": "New Name"})
-    
     col_def = columns_manager._get_col_def_from_col_id("name")
     assert col_def.title == "New Name"
   

tests/core/test_utils.py

@@ -1,6 +1,6 @@
 import pytest
 
-from myfasthtml.core.utils import flatten, make_html_id, pascal_to_snake, snake_to_pascal
+from myfasthtml.core.utils import flatten, make_html_id, pascal_to_snake, snake_to_pascal, make_unique_safe_id
 
 
 @pytest.mark.parametrize("input_args,expected,test_description", [
@@ -57,6 +57,7 @@ def test_i_can_flatten(input_args, expected, test_description):
   result = flatten(*input_args)
   assert result == expected, f"Failed for test case: {test_description}"
 
+
 @pytest.mark.parametrize("string, expected", [
     ("My Example String!", "My-Example-String_"),
     ("123 Bad ID", "id_123-Bad-ID"),
@@ -82,9 +83,9 @@ def test_i_can_have_valid_html_id(string, expected):
     ("   ", "", "only spaces"),
 ])
 def test_i_can_convert_pascal_to_snake(input_str, expected, test_description):
-    """Test that pascal_to_snake correctly converts PascalCase/camelCase to snake_case."""
-    result = pascal_to_snake(input_str)
-    assert result == expected, f"Failed for test case: {test_description}"
+  """Test that pascal_to_snake correctly converts PascalCase/camelCase to snake_case."""
+  result = pascal_to_snake(input_str)
+  assert result == expected, f"Failed for test case: {test_description}"
 
 
 @pytest.mark.parametrize("input_str, expected, test_description", [
@@ -104,6 +105,18 @@ def test_i_can_convert_pascal_to_snake(input_str, expected, test_description):
     ("___", "", "only underscores"),
 ])
 def test_i_can_convert_snake_to_pascal(input_str, expected, test_description):
-    """Test that snake_to_pascal correctly converts snake_case to PascalCase."""
-    result = snake_to_pascal(input_str)
-    assert result == expected, f"Failed for test case: {test_description}"
+  """Test that snake_to_pascal correctly converts snake_case to PascalCase."""
+  result = snake_to_pascal(input_str)
+  assert result == expected, f"Failed for test case: {test_description}"
+
+
+@pytest.mark.parametrize("name, existing_ids, expected", [
+    (None, [], None),
+    ("MyClass", [], "myclass"),
+    ("MyClass", ["myclass"], "myclass_1"),
+    ("MyClass", ["myclass", "myclass_1"], "myclass_2"),
+])
+def test_make_unique_safe_id(name, existing_ids, expected):
+  assert make_unique_safe_id(name, existing_ids) == expected, (
+      f"Failed for name: {name}, existing_ids: {existing_ids}, expected: {expected}"
+  )