test_grid.py

import unittest
from grid import grid, is_winner

# python -m unittest discover tests

class TestGridWinner(unittest.TestCase):

    def test_first_row_is_winner(self):
        grid[0][0] = "x"
        grid[0][1] = "x"
        grid[0][2] = "x"
        self.assertTrue(is_winner("x"))

    def test_second_row_is_winner(self):
        grid[1][0] = "x"
        grid[1][1] = "x"
        grid[1][2] = "x"
        self.assertTrue(is_winner("x"))

    def test_third_row_is_winner(self):
        grid[2][0] = "x"
        grid[2][1] = "x"
        grid[2][2] = "x"
        self.assertTrue(is_winner("x"))

    def test_first_column_is_winner(self):
        grid[0][0] = "x"
        grid[1][0] = "x"
        grid[2][0] = "x"
        self.assertTrue(is_winner("x"))

    def test_second_column_is_winner(self):
        grid[0][1] = "x"
        grid[1][1] = "x"
        grid[2][1] = "x"
        self.assertTrue(is_winner("x"))

    def test_third_column_is_winner(self):
        grid[0][2] = "x"
        grid[1][2] = "x"
        grid[2][2] = "x"
        self.assertTrue(is_winner("x"))
    
    def test_fisrt_diagonal_is_winner(self):
        grid[0][0] = "x"
        grid[1][1] = "x"
        grid[2][2] = "x"
        self.assertTrue(is_winner("x"))

    def test_second_diagonal_is_winner(self):
        grid[0][2] = "x"
        grid[1][1] = "x"
        grid[2][0] = "x"
        self.assertTrue(is_winner("x"))