def test_str_with_complete_board_returns_correct_string():
"""Verifies that the string representation of a solved grid is correct."""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2), (2, 2), (2, 1), (2, 0)))
# Set path from "2"
draw_path(grid, ((1, 1), (1, 0), (2, 0)))
assert str(grid) == GRID_STRING_2
def test_is_head_complete_puzzle_returns_no_heads():
"""Verifies that a completely solved puzzle has no remaining heads."""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2), (2, 2), (2, 1), (2, 0)))
# Set path from "2"
draw_path(grid, ((1, 1), (1, 0), (2, 0)))
# Test that there are no heads anymore
assert not [point for row in grid for point in row if point.is_head()]
def test_get_next_with_no_child_and_some_open_neighbors_returns_first_available(
):
"""
Verifies that `get_next` returns the first available neighbor if some are open.
"""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set partial path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2)))
assert get_next(grid[1][1]).location == (2, 1)
def test_get_head_with_complete_puzzle_returns_none():
"""Verifies that a completely solved puzzle reports having no heads."""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2), (2, 2), (2, 1), (2, 0)))
# Set path from "2"
draw_path(grid, ((1, 1), (1, 0), (2, 0)))
assert not has_head(grid)
assert get_head(grid) is None
def test_reveal_with_complete_puzzle_prints_but_does_not_backtrack(capsys):
"""Verifies that `reveal` on a complete puzzle prints as expected."""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2), (2, 2), (2, 1), (2, 0)))
# Set path from "2"
draw_path(grid, ((1, 1), (1, 0), (2, 0)))
# Test reveal with no delay
reveal(grid, delay=0)
assert capsys.readouterr().out == f"\x1b[J{SOLVED_GRID_STRING}\n"
def mock_strategy(grid):
"""
Mock algorithm to be applied only to the following grid:
2 ·
* *
"""
draw_path(grid, ((0, 0), (0, 1), (1, 1)))
return True
def test_is_option_with_unavailable_neighbor_returns_false():
"""
Verifies that `is_option` correctly identifies when a point is not an option.
"""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set partial path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2)))
# Test neighbors on partial path from "3"
current = grid[1][1]
assert not is_option(current, grid[0][1])
assert not is_option(current, grid[1][2])
def test_get_head_with_incomplete_puzzle_returns_head():
"""Verifies that `get_head` on a partially solved puzzle returns a head."""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set partial path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2)))
# Test get_head returns head on path from "3"
assert has_head(grid)
assert get_head(grid).location == (0, 2)
grid[0][2].child = grid[1][2]
# Test get_head returns head on path from "2"
assert has_head(grid)
assert get_head(grid).location == (1, 1)
def test_is_head_with_sink_returns_false():
"""Verifies that a sink never reports being a head."""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Test sink with no parents
assert not grid[2][0].is_head()
# Set path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2), (2, 2), (2, 1), (2, 0)))
# Test sink with one parent
assert not grid[2][0].is_head()
# Set path from "2"
draw_path(grid, ((1, 1), (1, 0), (2, 0)))
# Test sink with all parents
assert not grid[2][0].is_head()
def test_remaining_segments_with_new_segment_returns_change():
"""
Verifies that moving to a new segment decrements the number of remaining segments.
"""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Test first point on second segment
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2)))
assert grid[1][2].remaining_segments == 2
# Test second point on second segment has no change
grid[1][2].child = grid[2][2]
assert grid[2][2].remaining_segments == 2
# Test first point on third segment
grid[2][2].child = grid[2][1]
assert grid[2][1].remaining_segments == 1
def test_has_relationship_with_relationship_returns_true():
"""Verifies that `has_relationship` returns true for related points."""
grid = Grid(((3, -1, -1), (-1, 2, -1), (0, -1, -1)))
# Set path from "3"
draw_path(grid, ((0, 0), (0, 1), (0, 2), (1, 2), (2, 2), (2, 1), (2, 0)))
# Set path from "2"
draw_path(grid, ((1, 1), (1, 0), (2, 0)))
# Test north center pipe point
assert grid[0][0].has_relationship(Direction.EAST)
assert grid[0][1].has_relationship(Direction.WEST)
assert grid[0][1].has_relationship(Direction.EAST)
assert grid[0][2].has_relationship(Direction.WEST)
# Test center center source point
assert grid[1][1].has_relationship(Direction.WEST)
assert grid[1][0].has_relationship(Direction.EAST)
# Test south west sink point
assert grid[1][0].has_relationship(Direction.SOUTH)
assert grid[2][0].has_relationship(Direction.NORTH)
assert grid[2][0].has_relationship(Direction.EAST)
assert grid[2][1].has_relationship(Direction.WEST)
def test_get_next_with_no_child_and_no_open_neighbors_returns_none():
"""Verifies that `get_next` returns None if no neighbors are open."""
grid = Grid(((4, -1, 1), (0, -1, -1), (-1, -1, 0)))
# Set (incorrect) path from "4"
draw_path(grid, ((0, 0), (0, 1), (1, 1), (1, 2), (2, 2)))
assert get_next(grid[1][2]) is None