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_eq():
    assert PolygonalChain((0, 1, 2)) == PolygonalChain((0, 1, 2))
    # pylint: disable=unneeded-not
    assert not PolygonalChain((0, 1, 2)) == PolygonalChain((0, 1, 4))
    assert not PolygonalChain((0, 1, 2)) == PolygonalChain((0, 4, 2))
    assert not PolygonalChain((0, 1, 2)) == PolygonalChain((4, 1, 2))
    assert not PolygonalChain((0, 1, 2)) == PolygonalChain((1, 2, 3, 4))
def test_adjacent_vertex_indices_2():
    chain = PolygonalChain((0, 1, 4, 8))
    pairs = list(chain.adjacent_vertex_indices(2))
    assert len(pairs) == 3
    assert pairs[0] == (0, 1)
    assert pairs[1] == (1, 4)
    assert pairs[2] == (4, 8)
def test_adjacent_vertex_indices_1():
    chain = PolygonalChain((0, 1, 4, 8))
    pairs = list(chain.adjacent_vertex_indices(1))
    assert len(pairs) == 4
    assert pairs[0] == (0, )
    assert pairs[1] == (1, )
    assert pairs[2] == (4, )
    assert pairs[3] == (8, )
def test_connect(vertex_indices_a, vertex_indices_b, expected_vertex_indices):
    chain = PolygonalChain(vertex_indices_a)
    chain.connect(PolygonalChain(vertex_indices_b))
    assert PolygonalChain(expected_vertex_indices) == chain
def test_repr():
    assert repr(PolygonalChain([])) == "PolygonalChain(vertex_indices=())"
    assert repr(PolygonalChain(
        (0, 2, 1))) == "PolygonalChain(vertex_indices=(0, 2, 1))"
    assert (repr(PolygonalChain(
        (0, 2, 1, 4, 3))) == "PolygonalChain(vertex_indices=(0, 2, 1, 4, 3))")
def test_eq_normalized():
    assert PolygonalChain((0, 1, 2)) == PolygonalChain((0, 2, 1))
    assert PolygonalChain((1, 0, 2)) == PolygonalChain((0, 2, 1))
    assert PolygonalChain((1, 0, 2, 4)) == PolygonalChain((0, 1, 4, 2))
    # pylint: disable=unneeded-not
    assert not PolygonalChain((1, 0, 2, 4)) == PolygonalChain((0, 1, 2, 4))
def test_normalized(indices_init, indices_normalized):
    assert (list(PolygonalChain(indices_init).normalized().vertex_indices) ==
            indices_normalized)
def test_reassign_vertex_indices():
    chain = PolygonalChain((0, 21, 42, 84))
    chain.vertex_indices = (1, 2, 3, 4)
    assert tuple(chain.vertex_indices) == (1, 2, 3, 4)
def test_init():
    chain = PolygonalChain((0, 21, 42, 84))
    assert tuple(chain.vertex_indices) == (0, 21, 42, 84)
def test_connect_fail_empty(vertex_indices_a, vertex_indices_b):
    chain = PolygonalChain(vertex_indices_a)
    with pytest.raises(Exception):
        chain.connect(PolygonalChain(vertex_indices_b))
def test_connect_fail(vertex_indices_a, vertex_indices_b):
    chain = PolygonalChain(vertex_indices_a)
    with pytest.raises(PolygonalChainsNotOverlapingError):
        chain.connect(PolygonalChain(vertex_indices_b))