Thank you! I'm not sure why [mutating the argument] didn't give a bad test result on all of them.

I don't know if this is the best solution, but I just added this line as the first line of my function:

args = args[:]

to make a separate copy of args to manipulate. After that, all my tests succeeded.

Classic one... ;)

Don't mutate the argument, it's bad practice (and it's what generate your troubles ;) )

I'm getting an issue with the random tests in Python.

There was a randome test with this input: [-69, -66, -65, -64, -63, -62, -59, -58, -55, -54, -53, -52]

and the test failed, giving me this error message:

It should work for random inputs too: '-69,-66--62,-59,-58,-55--52' should equal ''

I'm getting a lot of random tests where the unit test believes the output should be an empty string. Am I missing something in the instructions? I'm wondering if it's expecting '' because the input is invalid, but it doesn't look invalid to me.

@juliand665 -- ah! you're correct -- that makes sense.

There should really be more than one test case in the attempt to check for edge cases and prevent overfitting (and it's a kindness to have sample test cases pre-written :) )

Don't know much about ruby, but I'm pretty sure that's how they're converting the numbers to strings.

I don't know what post you're answering to, but what you're saying is false:
['this is', 'a good example'].join(' ') => 'this is a good example'
'this is a good example'.split(' ') => ['this', 'is', 'a', 'good', 'example']
thus ['this is', 'a good example'].join(' ').split(' ') => ['this', 'is', 'a', 'good', 'example']

Why are you doing join(" ").split(" ")?

arr.join(" ").split(" ") == arr

I realize that these kata are written for multiple languages, but in Ruby this should really be written as a predicate:

Array.same_structure_as?(other)

since it only returns a boolean.

ugh. this is so elegant I hate my solution.

The instructions should be more clear, or the test cases should provide more output.

The script I wrote fails on the third test, but there is inadequate information in the Instructions to know what additional circumstances I should account for.