Excellent kata.

no longer relevant, retired

no longer relevant, retired

There are no random tests.

How does it look possible and valid if the very first element was given as 4 and in the solution it becomes 1?

Check the first line: given [4,1,3,2] expected [1,4,3,2], it indeed looks strange 🤷‍♂️

Now I wonder how was that possible 🤔

Thanks

Your solution is wrong, check the first block:

 [[2, 4,...
  [4, 3,...

it's missing the 1

The 2x2 blocks should also contain the numbers 1-4.

for [[2, 0, 0, 1],
[0, 0, 1, 0],
[0, 2, 0, 0],
[0, 0, 0, 4]]
I have this response :
Expected: 'This sudoku is unsolvable!',
instead got: [[2, 4, 3, 1],
[4, 3, 1, 2],
[1, 2, 4, 3],
[3, 1, 2, 4]]
what am I missing here?
and there are also some random tests with the same problem.

What's wrong with it? Seems very possible and valid.

Issue too vague.

given board = [ [ 4, 1, 3, 2 ], [ 3, 0, 0, 1 ], [ 1, 0, 0, 3 ], [ 2, 0, 1, 4 ] ]

expected = [[1, 4, 3, 2], [2, 3, 4, 1], [4, 2, 1, 3], [3, 1, 2, 4]]

How is this possible!!

You should check your solution again. Found some test cases which are expected Unsolvable, instead got a grid with some zeros.

And somehow I see your console.log works.

all good but grid i am printing is not visible in random tests..how can someone debug ?

No need validate if test will be zero or one solution, right?

And now?