BUG: add UT to conver_value for this use case (pandas-dev#39189)

Author: nofarmish

pandas/tests/computation/test_pytables.py

@@ -0,0 +1,30 @@
+import pytest
+from typing import Any
+from unittest.mock import patch, PropertyMock
+from pandas.core.computation.pytables import BinOp, TermValue
+from pandas.core.series import Series
+
+
+@patch('pandas.core.computation.pytables.BinOp.kind', new_callable=PropertyMock, return_value='integer')
+@patch('pandas.core.computation.pytables.BinOp.meta', new_callable=PropertyMock, return_value='category')
+@patch('pandas.core.computation.pytables.BinOp.metadata', new_callable=PropertyMock, return_value=Series(data=['a', 'b', 's']))
+@pytest.mark.parametrize("value, expected_results",
+                         [('q',
+                           TermValue(-1, -1, 'integer')),
+                          ('a',
+                           TermValue(0, 0, 'integer'))])
+def test_convert_value(mock_kind,
+                       mock_meta,
+                       mock_metadata,
+                       value: Any,
+                       expected_results: TermValue):
+
+    with patch.object(BinOp, "__init__", lambda p1, p2, p3, p4, p5, p6: None):
+        bin_op = BinOp(None, None, None, None, None)
+        bin_op.encoding = 'UTF-8'
+
+        result = bin_op.convert_value(value)
+
+        assert result.kind == expected_results.kind and\
+               result.value == expected_results.value and\
+               result.converted == expected_results.converted