fix tests by casting enum to string for polars

marimo/_plugins/ui/_impl/tables/polars_table.py

@@ -154,6 +154,15 @@ def to_json_str(
                                 result, column
                             )
                             converted_columns.append(column.name)
+                        # https://github.com/marimo-team/marimo/issues/5562
+                        elif isinstance(dtype, pl.List) and isinstance(
+                            dtype.inner, (pl.Enum, pl.Categorical)
+                        ):
+                            # Convert each element in the list to a string
+                            result = result.with_columns(
+                                pl.col(column.name).cast(pl.List(pl.String))
+                            )
+                            converted_columns.append(column.name)
 
                     if converted_columns:
                         LOGGER.info(

tests/_plugins/ui/_impl/tables/test_polars_table.py

@@ -982,3 +982,19 @@ def test_to_json_binary(self) -> None:
         )
 
         data.write_json()
+
+    def test_to_json_enum_list_not_supported(self) -> None:
+        # When this is supported, we can remove the casting to string
+        import polars as pl
+
+        data = {"A": [["A", "B", "C"], ["A", "B", "C"], ["A", "B", "C"]]}
+
+        data_enum = pl.DataFrame(
+            data, schema={"A": pl.List(pl.Enum(categories=["A", "B", "C"]))}
+        )
+        with pytest.raises(pl.exceptions.PanicException):
+            data_enum.write_json()
+
+        data_list = pl.DataFrame(data, schema={"A": pl.List(pl.Categorical())})
+        with pytest.raises(pl.exceptions.PanicException):
+            data_list.write_json()