module LuhnTests open FsUnit.Xunit open Xunit open Luhn [] let ``Single digit strings can not be valid`` () = valid "1" |> should equal false [] let ``A single zero is invalid`` () = valid "0" |> should equal false [] let ``A simple valid SIN that remains valid if reversed`` () = valid "059" |> should equal true [] let ``A simple valid SIN that becomes invalid if reversed`` () = valid "59" |> should equal true [] let ``A valid Canadian SIN`` () = valid "055 444 285" |> should equal true [] let ``Invalid Canadian SIN`` () = valid "055 444 286" |> should equal false [] let ``Invalid credit card`` () = valid "8273 1232 7352 0569" |> should equal false [] let ``Invalid long number with an even remainder`` () = valid "1 2345 6789 1234 5678 9012" |> should equal false [] let ``Invalid long number with a remainder divisible by 5`` () = valid "1 2345 6789 1234 5678 9013" |> should equal false [] let ``Valid number with an even number of digits`` () = valid "095 245 88" |> should equal true [] let ``Valid number with an odd number of spaces`` () = valid "234 567 891 234" |> should equal true [] let ``Valid strings with a non-digit added at the end become invalid`` () = valid "059a" |> should equal false [] let ``Valid strings with punctuation included become invalid`` () = valid "055-444-285" |> should equal false [] let ``Valid strings with symbols included become invalid`` () = valid "055# 444$ 285" |> should equal false [] let ``Single zero with space is invalid`` () = valid " 0" |> should equal false [] let ``More than a single zero is valid`` () = valid "0000 0" |> should equal true [] let ``Input digit 9 is correctly converted to output digit 9`` () = valid "091" |> should equal true [] let ``Very long input is valid`` () = valid "9999999999 9999999999 9999999999 9999999999" |> should equal true [] let ``Valid luhn with an odd number of digits and non zero first digit`` () = valid "109" |> should equal true [] let ``Using ascii value for non-doubled non-digit isn't allowed`` () = valid "055b 444 285" |> should equal false [] let ``Using ascii value for doubled non-digit isn't allowed`` () = valid ":9" |> should equal false [] let ``Non-numeric, non-space char in the middle with a sum that's divisible by 10 isn't allowed`` () = valid "59%59" |> should equal false