it works because you return early if you find the result, otherwise the methods last line is return nil

Are you sure you're not mixing the expected values from one test with the log of the next one?

The test in Ruby are all messed up. For example:

Expected: "tvuqkuur", instead got: "noxxrexue"
Log
"Testing for 'oewkkhwiz jblrxp afgdjuo jqzddoqf lnswna sidbmtxneqj nvlh goqculuiuon ovbnea znj ii mzzktfqvgx yoiqszkwvm wzumec'"
"Expecting 'yoiqszkwvm'"

It says it expects two different words....