from unittest import TestCase

from pseudoku.grid import Grid

class SudokuTestCase(TestCase):
    """TestCase subclass that provides some convenience methods for testing
    sudoku puzzles.
    """
    
    def assertSolvable(self, grid, msg=None):
        """Asserts that the given puzzle, when run through Grid.solve(),
        produces a filled grid.

        grid may be either a Grid object or a string.
        """

        if type(grid) == str:
            grid = Grid.from_string(grid)

        grid.solve()
        self.assertTrue(grid.filled, msg)