def _step_moving_obstacle(grid: Grid,
position: Position,
*,
rng: Optional[rnd.Generator] = None):
"""Utility for moving a single MovingObstacle randomly"""
assert isinstance(grid[position], MovingObstacle)
rng = get_gv_rng_if_none(rng)
next_positions = [
next_position
for next_position in get_manhattan_boundary(position, distance=1)
if next_position in grid and isinstance(grid[next_position], Floor)
]
try:
next_position = rng.choice(next_positions)
except ValueError:
pass
else:
grid.swap(position, next_position)
def test_grid_swap():
grid = Grid(3, 4)
# caching positions and objects before swap
objects_before = {
position: grid[position]
for position in grid.positions()
}
pos1 = Position(0, 0)
pos2 = Position(1, 1)
grid.swap(pos1, pos2)
# caching positions and objects after swap
objects_after = {position: grid[position] for position in grid.positions()}
# testing swapped objects
assert objects_before[pos1] is objects_after[pos2]
assert objects_before[pos2] is objects_after[pos1]
# testing all other objects are the same
for position in grid.positions():
if position not in (pos1, pos2):
assert objects_before[position] is objects_after[position]