text: import unittest
  
  from spiral_matrix import spiral_matrix
  
  # Tests adapted from `problem-specifications//canonical-data.json`
  
  
  class SpiralMatrixTest(unittest.TestCase):
      def test_empty_spiral(self):
          self.assertEqual(spiral_matrix(0), [])
  
      def test_trivial_spiral(self):
          self.assertEqual(spiral_matrix(1), [[1]])
  
      def test_spiral_of_size_2(self):
          self.assertEqual(spiral_matrix(2), [[1, 2], [4, 3]])
  
      def test_spiral_of_size_3(self):
          self.assertEqual(spiral_matrix(3), [[1, 2, 3], [8, 9, 4], [7, 6, 5]])
  
      def test_spiral_of_size_4(self):
          self.assertEqual(
              spiral_matrix(4),
              [[1, 2, 3, 4], [12, 13, 14, 5], [11, 16, 15, 6], [10, 9, 8, 7]],
          )
  
      def test_spiral_of_size_5(self):
          self.assertEqual(
              spiral_matrix(5),
              [
                  [1, 2, 3, 4, 5],
                  [16, 17, 18, 19, 6],
                  [15, 24, 25, 20, 7],
                  [14, 23, 22, 21, 8],
                  [13, 12, 11, 10, 9],
              ],
          )
  
  
  if __name__ == "__main__":
      unittest.main()
  