Tipalti API name support via fuzzing

main.py

# Last updated: 2022-01-04
def is_valid_tipalti_name(name):
    # https://support.tipalti.com/Content/Topics/Development/APIs/PayeeAPI/UpdatePayee/CreatePayeeInfoAutoIdap/Intro.htm#PayeeDetailsItem1
    #   Max length: 70 -- Incorrect: During testing it's 35 characters...
    #   Latin and numeric (cannot be only numeric)
    #   Spaces, periods, dashes (cannot be the first character)—e.g., "Mary Jo", "Jr.", "Mary-Jo"
    #   We've found additional cases like "Test 4" which fail, see tests for robust overview

    # Their API truncates names at 35 characters
    #   This is fine for our use case and we won't reject a name for being too long

    # If we contain any unexpected characters, reject it
    if re.search(r'[^A-Za-z -\.]', name):
        return False

    # Split up our name into words, filter out empty ones
    words = name.split(' ')
    words = [word for word in words if word]

    # If we have no words, stop (means was empty string or only spaces)
    if not words:
        return False

    # Validate each word
    for word in words:
        if word[0] in ['-', '.'] or word[-1] in ['-']:
            return False
        # DEV: We won't run into an IndexError as that implies the word was only '.', which is covered by last `if`
        if word.rstrip('.')[-1] in ['-']:
            return False
    return True

test.py

# Last updated: 2022-01-04
class TipaltiUtilsTestCase(TestCase):
    def test_is_valid_tipalti_name(self):
        """Verify is_valid_tipalti_name lines up to API expectations"""
        # Sanity checked directly via API calls
        # Basic test case
        self.assertEqual(is_valid_tipalti_name('foo'), True)

        # Numbers disallowed in all forms - docs say valid, reality says no
        self.assertEqual(is_valid_tipalti_name('1'), False)
        self.assertEqual(is_valid_tipalti_name('foo4'), False)
        self.assertEqual(is_valid_tipalti_name('foo4bar'), False)

        # Dealing with spaces
        self.assertEqual(is_valid_tipalti_name('foo bar'), True)
        self.assertEqual(is_valid_tipalti_name('foo '), True)  # Truncated to 'foo', which is valid
        self.assertEqual(is_valid_tipalti_name('foo   '), True)  # Truncated to 'foo', which is valid
        self.assertEqual(is_valid_tipalti_name(' '), False)  # Truncated to '', which is technically valid but not for us

        # Disallowed characters
        self.assertEqual(is_valid_tipalti_name('föo'), False)

        # Excepted characters (already dealt with spaces in isolation)
        self.assertEqual(is_valid_tipalti_name('foo-'), False)  # Docs say valid, reality says no
        self.assertEqual(is_valid_tipalti_name('foo -'), False)
        self.assertEqual(is_valid_tipalti_name('foo - bar'), False)

        self.assertEqual(is_valid_tipalti_name('foo-bar'), True)
        self.assertEqual(is_valid_tipalti_name('foo -bar'), False)

        self.assertEqual(is_valid_tipalti_name('foo.'), True)
        self.assertEqual(is_valid_tipalti_name('foo.bar'), True)
        self.assertEqual(is_valid_tipalti_name('foo .bar'), False)

        self.assertEqual(is_valid_tipalti_name('foo-.'), False)  # Fun edge case
        self.assertEqual(is_valid_tipalti_name('foo-bar.'), True)