OP solved it, closing

Good for you. Here in JS we have to write them ourselves.

Thanks for the sample test. This one helped me work it out. Greatly appreciated :)

Like how u used regex there! Also, if you went to App Academy, I'd love hear about your experience, are you open to emailing me (I just got accepted to a/A)?

I belive that you are confused for "West" with "Left".
Taking 4 Lefts will return you to same point but walking towards west 4 times won't bring you back to point where you started.

It's recommended to fill in the exmaple tests but are not mandatory, and since only a few tests is already mostly sufficient to test for correctness it's not that much of an issue.

Interesting how reverse_it(true) does not look for "false", but for "true".

Expect error: "Omae wa mo shindeiru". Look at the output more carefully.

The author gave us the maximum size to be expected, so I see no point in worrying about it.

Exploit!! ahahah

fails if seq.size > this example

It DOES NOT ask you to find odd numbers. It asks you to find odd occurrences of the digits. It does not mean the digits itself cannot be even. Read kata's descriptions carefully, lol.

Constraints: 2 ≤ sequence.length ≤ 1000

What's the problem?(I don't understand array with length 100_000+) ;-)

Surprised that myjinxin2015 didn't make a test case for execution time like he usually does. Found one accepted Ruby solution that should fail for array with length 100_000+ .