Bug: Greatest Subsequential Sum exercise is not testing my solution with numbers. Instead an Object with Chai test assertions gets passed to the function

Tell us what’s happening:
This is similar to a bug I filed a few hours ago for another exercise I was working on.

This exercise is supposed to test my function with a sequence or array of numbers. Instead, what is getting passed to my function is an Object with a Chai assertion string as one of its properties. The problem can be replicated using the code below.

Here is a screenshot of the problem using Chrome: https://imgur.com/a/SylONne

It also happens with Firefox.

Your code so far

function maximumSubsequence (population) {
  // Good luck!

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge: