add meta test for code editor params

tests/text_area/test_code_editor.py

@@ -0,0 +1,18 @@
+import inspect
+
+from textual.widgets import TextArea
+
+
+def test_code_editor_parameters_kept_up_to_date():
+    """Meta test to ensure the `TextArea.code_editor` convenience constructor
+    is kept up to date with changes to the `TextArea.__init__` parameters.
+    """
+    text_area_params = inspect.signature(TextArea.__init__).parameters
+    code_editor_params = inspect.signature(TextArea.code_editor).parameters
+    expected_diffs = ["theme", "soft_wrap", "tab_behavior", "show_line_numbers"]
+    for param in text_area_params:
+        if param == "self":
+            continue
+        assert param in code_editor_params
+        if param not in expected_diffs:
+            assert code_editor_params[param] == text_area_params[param]