Imports Xunit Public Class LuhnTests Public Sub Single_digit_strings_can_not_be_valid() Assert.False(IsValid("1")) End Sub Public Sub A_single_zero_is_invalid() Assert.False(IsValid("0")) End Sub Public Sub A_simple_valid_sin_that_remains_valid_if_reversed() Assert.True(IsValid("059")) End Sub Public Sub A_simple_valid_sin_that_becomes_invalid_if_reversed() Assert.True(IsValid("59")) End Sub Public Sub A_valid_canadian_sin() Assert.True(IsValid("055 444 285")) End Sub Public Sub Invalid_canadian_sin() Assert.False(IsValid("055 444 286")) End Sub Public Sub Invalid_credit_card() Assert.False(IsValid("8273 1232 7352 0569")) End Sub Public Sub Invalid_long_number_with_an_even_remainder() Assert.False(IsValid("1 2345 6789 1234 5678 9012")) End Sub Public Sub Invalid_long_number_with_a_remainder_divisible_by_5() Assert.False(IsValid("1 2345 6789 1234 5678 9013")) End Sub Public Sub Valid_number_with_an_even_number_of_digits() Assert.True(IsValid("095 245 88")) End Sub Public Sub Valid_number_with_an_odd_number_of_spaces() Assert.True(IsValid("234 567 891 234")) End Sub Public Sub Valid_strings_with_a_non_digit_added_at_the_end_become_invalid() Assert.False(IsValid("059a")) End Sub Public Sub Valid_strings_with_punctuation_included_become_invalid() Assert.False(IsValid("055-444-285")) End Sub Public Sub Valid_strings_with_symbols_included_become_invalid() Assert.False(IsValid("055# 444$ 285")) End Sub Public Sub Single_zero_with_space_is_invalid() Assert.False(IsValid(" 0")) End Sub Public Sub More_than_a_single_zero_is_valid() Assert.True(IsValid("0000 0")) End Sub Public Sub Input_digit_9_is_correctly_converted_to_output_digit_9() Assert.True(IsValid("091")) End Sub Public Sub Very_long_input_is_valid() Assert.True(IsValid("9999999999 9999999999 9999999999 9999999999")) End Sub Public Sub Valid_luhn_with_an_odd_number_of_digits_and_non_zero_first_digit() Assert.True(IsValid("109")) End Sub Public Sub Using_ascii_value_for_non_doubled_non_digit_isnt_allowed() Assert.False(IsValid("055b 444 285")) End Sub Public Sub Using_ascii_value_for_doubled_non_digit_isnt_allowed() Assert.False(IsValid(":9")) End Sub Public Sub Non_numeric_non_space_char_in_the_middle_with_a_sum_thats_divisible_by_10_isnt_allowed() Assert.False(IsValid("59%59")) End Sub End Class