yes, very good point. but it only effects it if the comma is in the last person in the array.

Do you know someone whose name include a comma?)

this error message is very unclear:
"Expected: equal to This kata is very interesting!
Actual: This kata is very interesting!"

No trailing spaces.

only if it is the last name

Are you using python? I had the same issue you are reporting with the python test case is because the test is passing the same array to both the function and the validation since it should be the same. I was actually changing that original array and returning a new one, and it validated the new array againt the one I changed.

Technically, that's a feature of python that the array passed to function is not being copied but being changed globally. But for the cleanliness of the test, it should probably be tested against a different array.

Similar issue here: 2x2 becomes a 3x3 grid in expectation.
When I write a workaround for it, the test expects the 2x2 again.

But it works with perfectly spherical chickens in vacuum :)

in the test cases there one, where got a 2x2 grid and the kata expects to return a 4x4 grid....WHY?
The description mentioned that the size of the world NEVER grow

i guess it wont work if someones name include a comma :P