Ruby 3.0 should be enabled, read this to learn how to do it

Please organize the structure of test fixture as following (although it has been mentioned in the attached link, I'm repeated here again)

describe "<This message should describe the categories of test groups inside this block>" do
  it "<A short message describing this test group>" do
    expect(...).to eq(...) #Assertions
    #Or Test.assert_equals(user_response, reference_response)
  end
end

Added new test case for Python and JS.

The method you're trying to use is not available in the Node version currently supported by CW.

1)it is not valid after anter69 made the change
2)the solution whose link you've replied is valid.

the first link posted below is still valid (see FArekkusu message)

Greatly enjoyed solving this. Thanks for making it!

But I do want to bemoan the choice to have the zero tile in the bottom right rather than the top left, haha.

Added a test case to all current languages to prevent this:

[[6,7,8], [0,1,2], [3,4,5]]  -->  False

same with this one

An incorrect solution may pass the tests.

Done. Thanks!

Fixed.