mergesort_test

mergesort_test.py

import unittest
from mergesort import MergeSort

class MergeSortTest(unittest.TestCase):
  
  def setUp(self):
    self.under_test = MergeSort()
    
  def test_empty_array(self):
    array_to_sort = []
    sorted_array = MergeSort.sort(array_to_sort)
    self.assertEqual([], array_to_sort)
  
  def test_single_element(self):
    array_to_sort = [1]
    sorted_array = MergeSort.sort(array_to_sort)
    self.assertEqual([1], sorted_array)

  def test_two_elements_sorted(self):
    array_to_sort = [1, 2]
    sorted_array = MergeSort.sort(array_to_sort)
    self.assertEqual([1, 2], sorted_array)

  def test_two_elements_not_sorted(self):
    array_to_sort = [2, 1]
    sorted_array = MergeSort.sort(array_to_sort)
    self.assertEqual([1, 2], sorted_array)

  def test_three_elements_not_sorted(self):
    array_to_sort = [2, 1, 3]
    sorted_array = MergeSort.sort(array_to_sort)
    self.assertEqual([1, 2, 3], sorted_array)

  def test_three_elements_sorted(self):
    array_to_sort = [1,2,3]
    sorted_array = MergeSort.sort(array_to_sort)
    self.assertEqual([1, 2, 3], sorted_array)

  def test_many_elements(self):
    array_to_sort = [2, 1, 70, 8, 4, 45, 7, 7]
    sorted_array = MergeSort.sort(array_to_sort)
    self.assertEqual([1, 2, 4, 7, 7, 8, 45, 70], sorted_array)