def test_segments():
chain = PolygonalChain((0, 1, 4, 8))
segments = list(chain.segments())
assert len(segments) == 3
assert segments[0] == LineSegment((0, 1))
assert segments[1] == LineSegment((1, 4))
assert segments[2] == LineSegment((4, 8))
def test_adjacent_vertex_indices_3():
chain = LineSegment((1, 4))
triplets = list(chain.adjacent_vertex_indices(3))
assert len(triplets) == 2
assert triplets[0] == (1, 4, 1)
assert triplets[1] == (4, 1, 4)
def test_adjacent_vertex_indices_2():
chain = LineSegment((1, 4))
pairs = list(chain.adjacent_vertex_indices(2))
assert len(pairs) == 2
assert pairs[0] == (1, 4)
assert pairs[1] == (4, 1)
def test_adjacent_vertex_indices_1():
chain = LineSegment((1, 4))
singles = list(chain.adjacent_vertex_indices(1))
assert len(singles) == 2
assert singles[0] == (1, )
assert singles[1] == (4, )
def test_repr():
assert (repr(LineSegment(
(67018, 67019))) == "LineSegment(vertex_indices=(67018, 67019))")
def test_eq():
assert LineSegment((67018, 67019)) == LineSegment((67018, 67019))
assert LineSegment((67018, 67019)) == LineSegment((67019, 67018))
assert LineSegment((67019, 67018)) == LineSegment((67018, 67019))
def test_init_fail():
with pytest.raises(Exception):
LineSegment((1, 2, 3))