sudoku-solver/tests.py

"""All tests for the Sudoku Solver."""

import unittest
from main import iterate_board
from board import Board
from square import Square


class TestMain(unittest.TestCase):
    """TestCase for the main file."""

    def test_iterate_over_various_board_difficulties(self):
        """Run the solver on different boards."""

        strings = [(
            ".2..785..\n"
            "4...52...\n"
            "..1..3.2.\n"
            ".....1...\n"
            "7348.526.\n"
            "2.9.67..5\n"
            ".687..3.9\n"
            "342.1.7..\n"
            "19..86..2\n"
        ), (
            "..1..6435\n"
            ".....1...\n"
            ".5.47.98.\n"
            "..2.8.7.9\n"
            "..87..612\n"
            ".64.1..5.\n"
            "91.3428.7\n"
            ".27....9.\n"
            "6.3.9.5..\n"
        ), (
            ".....6...\n"
            "..2.35.8.\n"
            "....2..13\n"
            ".2....19.\n"
            "93....7..\n"
            "5....4...\n"
            "1......7.\n"
            ".7...142.\n"
            ".9.4.3...\n"
        ), (
            "...82....\n"
            "...6.9..1\n"
            "9.4..1...\n"
            ".9.7..28.\n"
            ".......57\n"
            "7.5......\n"
            ".78962..5\n"
            ".2..8.7.3\n"
            ".6..74.2.\n"
        ), (
            "4......1.\n"
            ".15.4.6..\n"
            ".....7...\n"
            "...21...8\n"
            "...734..2\n"
            ".3..8....\n"
            "8.19...45\n"
            ".4....7..\n"
            "2....3...\n"
        ), (
            "3........\n"
            ".6...791.\n"
            ".....325.\n"
            ".19.645..\n"
            ".......6.\n"
            ".85......\n"
            "...8.....\n"
            "..1..97..\n"
            "47..5....\n"
        )]

        for string in strings[:-4]:
            while '.' in string:
                new_string = iterate_board(string)
                self.assertNotEqual(new_string, string)
                string = new_string


class TestBoard(unittest.TestCase):
    """TestCase for Board."""

    def setUp(self):
        self.string = (
            ".2..785..\n"
            "4...52...\n"
            "..1..3.2.\n"
            ".....1...\n"
            "7348.526.\n"
            "2.9.67..5\n"
            ".687..3.9\n"
            "342.1.7..\n"
            "19..86..2\n"
        )
        self.board = Board(self.string)

    def test_lines_are_correctly_initialized(self):
        """There should be 9 lines, each a set of its values."""

        self.assertIsInstance(self.board.lines, list)
        self.assertEqual(len(self.board.lines), 9)

        for line in self.board.lines:
            self.assertIsInstance(line, set)
            self.assertNotEqual(len(line), 0)

    def test_columns_are_correctly_initialized(self):
        """There should be 9 columns, each a set of its values."""

        self.assertIsInstance(self.board.columns, list)
        self.assertEqual(len(self.board.columns), 9)

        for column in self.board.columns:
            self.assertIsInstance(column, set)
            self.assertNotEqual(len(column), 0)

    def test_grids_are_correctly_initialized(self):
        """There should be 9 grids, each a set of its values."""

        self.assertIsInstance(self.board.grids, list)
        self.assertEqual(len(self.board.grids), 9)

        for grid in self.board.grids:
            self.assertIsInstance(grid, set)
            self.assertNotEqual(len(grid), 0)

    def test_squares_are_correctly_initialized(self):
        """At instantiation, squares should be an empty list."""

        self.assertIsInstance(self.board.squares, list)
        self.assertEqual(len(self.board.squares), 0)


class TestSquare(unittest.TestCase):
    """TestCase for Square."""

    def setUp(self):
        content = '.'
        self.board = [
            Square(line, column, content)
            for line in range(9)
            for column in range(9)
        ]

        self.assertEqual(len(self.board), 81)

    def test_grid_is_correctly_computed(self):
        """Square.grid is correctly computed for all values."""

        correct_grids = (
            "000111222"
            "000111222"
            "000111222"
            "333444555"
            "333444555"
            "333444555"
            "666777888"
            "666777888"
            "666777888"
        )

        for i, square in enumerate(self.board):
            self.assertEqual(square.grid_id, int(correct_grids[i]))


if __name__ == '__main__':
    unittest.main()