def test_subtract_rectangle_with_shared_boundaries():
rect1 = Rectangle(0, 0, 20, 20)
rect2 = Rectangle(10, 0, 10, 10)
diff_rects = list(subtract(rect1, rect2))
assert len(diff_rects) == 2
assert Rectangle(0, 10, 20, 10) in diff_rects
assert Rectangle(0, 0, 10, 10) in diff_rects
def test_subtract_rectangle_inside_another():
outer = Rectangle(0, 0, 20, 20)
inner = Rectangle(5, 5, 10, 10)
diff_rects = list(subtract(outer, inner))
assert len(diff_rects) == 4
assert Rectangle(0, 0, 20, 5) in diff_rects
assert Rectangle(0, 5, 5, 10) in diff_rects
assert Rectangle(15, 5, 5, 10) in diff_rects
assert Rectangle(0, 0, 20, 5) in diff_rects
def test_subtract_rectangle_from_itself():
rect1 = Rectangle(0, 0, 20, 20)
rect2 = Rectangle(0, 0, 20, 20)
assert len(list(subtract(rect1, rect2))) == 0
def test_another_subtract():
rect1 = Rectangle(20, 0, 10, 10)
rect2 = Rectangle(15, -5, 20, 20)
diff_rects = list(subtract(rect1, rect2))
assert len(diff_rects) == 0
def test_subtract_nonintersecting_rectangle():
rect1 = Rectangle(0, 0, 20, 20)
rect2 = Rectangle(30, 0, 20, 20)
diff_rects = list(subtract(rect1, rect2))
assert len(diff_rects) == 1
assert diff_rects == [rect1]
def test_subtract_outer_rectangle_from_inner_rectangle():
outer = Rectangle(0, 0, 20, 20)
inner = Rectangle(5, 5, 10, 10)
assert len(list(subtract(inner, outer))) == 0