Test case: you_can_validate_from_a_u32 for luhn-from and luhn-trait is not correct.

[harishjp]

Here is the result of manual computation. I noticed that it is derived from "046 454 286" But the trouble is the leading 0 is ignored for the integer and hence the luhn value is different.

Test: 46_454_286
Expression: 4 + (6 * 2 - 9) + 4 + (5 * 2 - 9) + 4 + (2 * 2) + 8 + (6 * 2 - 9) = 31

[petertseng]

leading zeroes shouldn't matter though.

In "046 454 286", you double every second digit from the right: that's the 8, 4, 4, and 4.

In "46 454 286", you double every second digit from the right: that's the 8, 4, 4, and 4.

The same digits are doubled, so any number of leading zeroes makes no difference, since they're all added at the left end, not the right end.

Thus, I believe the tests currently in the track are correct as-is. Let us know if the above comment forgot to take something into consideration.

[harishjp]

:-) Thanks. This is awesome, I did this from left to right all this time and the tests passed except this one. Do not know how I missed right to left.

[petertseng]

I think it's because all the tests had odd number of characters, so left-to-right vs right-to-left did not matter. If we had a test for "59", we would have caught that. The test was recently added in #253.