Added CompoundIdentifier class is_input_header negative test

test/test_compound_identifier.py

@@ -10,6 +10,11 @@ def test_is_input_header_positive(compound_identifier, header):
     """Test that valid input headers return True."""
     assert compound_identifier.is_input_header(header) is True
 
+@pytest.mark.parametrize("header", ["output", "invalid", "InChI", "inchikey"])
+def test_is_input_header_negative(compound_identifier, header):
+    """Test that invalid input headers return False."""
+    assert compound_identifier.is_input_header(header) is False
+
 @pytest.mark.parametrize("header", ["key", "inchiKey", "KEY", "INCHIKEY"])
 def test_is_key_header_positive(compound_identifier, header):
     """Test that valid key headers return True."""