fix: handle None drop_na_params during replay to prevent AttributeError

[gitadi2]

Fixes

#199

Type of Change

• Bug fix

Problem

Projects containing a dropNa transformation without parameters cannot be saved or reverted. When drop_na_params is serialized as None by Pydantic, the replay handler calls .get("columns") on None, causing an AttributeError.

Root Cause

The line:

columns = action_details.get("drop_na_params", {}).get("columns")

The default {} only applies when the key is missing. When the key exists with value None, .get() returns None, and calling .get("columns") on None crashes.

Fix

columns = (action_details.get("drop_na_params") or {}).get("columns")

Using or {} converts None to an empty dict, so .get("columns") always works.

Testing

• Manual testing
• Existing tests pass

Checklist

• My code follows the project's style guidelines
• I have performed a self-review
• My changes generate no new warnings