Fixed.

There are lots of katas which say things like that but don't enforce them in the tests

Then those katas are badly made, aren't they?

I am not sure this is an issue, there are lots of katas which say things like that but don't enforce them in the tests. It also would be fairly non-trivial because of the many ways you can do this in various languages.

Has description conflicts.

Wow, it was worse than I thought, the random tests were in the sample tests tab, disclosing the solution. Fixed.

No random tests in Ruby.

You should do this without converting the inputted number into a string.

That's not tested at all in Python and Ruby (couldn't check it in Shell).

Last sample test for shell states "Solution for parameter '1020'" but it's actually testing 1001.

Left padding zeros has no mathematical sense, it's ok like that.

Its broken in shell-- trailing zeros are deleted in the test cases. Is this intended?

So for example 12300 becomes 321.