No sample, fixed tests and insufficient random test coverage for cases where a box has been formed, and winning is not possible such as:

[ [ [ 1, 1 ], [ 1, 2 ] ],
  [ [ 1, 1 ], [ 2, 1 ] ],
  [ [ 0, 0 ], [ 0, 1 ] ],
  [ [ 1, 2 ], [ 2, 2 ] ],
  [ [ 2, 1 ], [ 2, 2 ] ] ]

Here is a sample of a solution that should not pass