TST(string dtype): Resolve to_latex xfail (#60614)

TST(string dtype): Fix to_latex xfail

Author: rhshadrach

pandas/io/formats/style.py

@@ -1644,7 +1644,7 @@ def _update_ctx_header(self, attrs: DataFrame, axis: AxisInt) -> None:
         for j in attrs.columns:
             ser = attrs[j]
             for i, c in ser.items():
-                if not c:
+                if not c or pd.isna(c):
                     continue
                 css_list = maybe_convert_css_to_tuples(c)
                 if axis == 0:

pandas/tests/io/formats/style/test_to_latex.py

@@ -3,8 +3,6 @@
 import numpy as np
 import pytest
 
-from pandas._config import using_string_dtype
-
 from pandas import (
     DataFrame,
     MultiIndex,
@@ -731,7 +729,6 @@ def test_longtable_caption_label(styler, caption, cap_exp, label, lab_exp):
     )
 
 
-@pytest.mark.xfail(using_string_dtype(), reason="TODO(infer_string)", strict=False)
 @pytest.mark.parametrize("index", [True, False])
 @pytest.mark.parametrize(
     "columns, siunitx",