It should be stated in the description that the returned object shouldn't have a key with the name of "secret".

I'm sorry, but there are no tests for JavaScript version of this kata.
Do we have to write it ourselves (which is frankly not as bad as it sounds, but still)?

Nice Kata. In addition to getSecret() and setSecret I also had a secret property. The error message I got was:
"no property called 'secret'"
It took me way to long to figure out I just needed to remove the secret property.

I feel something like:
"There should be no secret property"
would be much more effective.

Am I the only one who gets all tests to pass, but then gets a console.log is undefined error, preventing the test from succeeding?