Thanks for your post. Good to double check but the first random testing function is no more there. I used in it something like expect_equal(matrix1, matrix2). I replaced it by something like the fixed tests function. Tell me if you find something!

Our returns have the same elements but were not taken as the same.

now it passes all the tests!
thank you. great kata!
btw I am double checking your solution to see what might cause the error

Doesn't seem easy to test matrix equality with expect_equal. I changed a bit the random testing function. Could you tell me if it works better for you now? (My solution passed the first version of random tests without problem but is it a proof?)
New publishing seems to take long.

Good, thanks for your post!