Your code doesn't run anywhere, since you wrote the last operator the wrong way around.
If that's fixed, it will still not work, as you return undefined instead of 0 when there are no sheep.

This test works great for me in browser, nodejs.. but not on this site. I just do a simple grouping function, so I get an object with the number of true, false, null and undefined. I then just return the number of trues from the object. This fails in this test.

I have the same problem. Problem is that my code works great in the browser when I try it.. but here it just says I return undefined.

same here!. I have trying to find the error in my code for an hour lol. Then I realised its the test that its at fault.

this was broken. Since many solutions would not even work on real sites.