The instructions aren't complete for Java. It isn't clear that you have to create your own dictionary for Java. Please provide the dictionary or improve the instructions.

The instruction wording is challenging to understand. Perhaps instead of "Your task is to return the first longest string consisting of k consecutive strings taken in the array." it would be better to say "Your task is to return the longest string consisting of k consecutive string taken from the array. If there is a tie for longest string, return the first one."

For Ruby, the "expect" test in the provided Tests has syntax errors.

The instructions could be clarified to include that spaces in the original should be replaced with underscore. Or, leave the spaces issue alone and ask for a String[] as the result.