def test_simple_case_from_start_without_whitespace():
"""
Make sure that we test a simple extraction from the start of the string without whitespace.
"""
# Arrange
input_string = " this is a test"
start_index = 0
character_to_match = " "
expected_output = (0, 0)
# Act
actual_output = ParserHelper.collect_backwards_while_one_of_characters(
input_string, start_index, character_to_match)
# Assert
assert expected_output == actual_output
def test_empty_string_with_good_index():
"""
Make sure that an empty string is handled properly with a good index
"""
# Arrange
input_string = ""
start_index = 0
character_to_match = " "
expected_output = (0, 0)
# Act
actual_output = ParserHelper.collect_backwards_while_one_of_characters(
input_string, start_index, character_to_match)
# Assert
assert expected_output == actual_output
def test_simple_case_from_end_with_eol_index():
"""
Make sure that we test a simple extraction from the end of the string with whitespace
"""
# Arrange
input_string = "this is a test "
start_index = -1
character_to_match = " "
expected_output = (2, len(input_string) - 2)
# Act
actual_output = ParserHelper.collect_backwards_while_one_of_characters(
input_string, start_index, character_to_match)
# Assert
assert expected_output == actual_output
def test_empty_string_with_bad_left_index():
"""
Make sure that an empty string is handled properly with an index that is too far to the left.
"""
# Arrange
input_string = ""
start_index = -2
character_to_match = " "
expected_output = (None, None)
# Act
actual_output = ParserHelper.collect_backwards_while_one_of_characters(
input_string, start_index, character_to_match)
# Assert
assert expected_output == actual_output
def remove_final_whitespace(self):
"""
Remove any final whitespace. Used by paragraph blocks so that they do not
end with a hard break.
"""
removed_whitespace = ""
(
collected_whitespace_length,
first_non_whitespace_index,
) = ParserHelper.collect_backwards_while_one_of_characters(
self.token_text, -1, Constants.whitespace)
if collected_whitespace_length:
removed_whitespace = self.token_text[
first_non_whitespace_index:first_non_whitespace_index +
collected_whitespace_length]
self.token_text = self.token_text[0:first_non_whitespace_index]
return removed_whitespace
