def test_point_at():
"""Check point_at is correct."""
s = LineSegment(Point(0, 0, 'A'), Point(1, 1, 'B'))
with pytest.raises(TypeError) as excinfo:
s.point_at('a')
assert str(excinfo.value) == 'position must be a number, found ' \
'<class \'str\'> instead.'
assert s.point_at(Number('0.5')) == s.midpoint()
assert s.point_at(Number('0.75')) == Point('0.75', '0.75')
assert s.point_at(Number(2)) == Point(2, 2)
assert s.point_at(0) == Point(0, 0)
assert s.point_at(1) == Point(1, 1)
assert s.point_at(-2) == Point(-2, -2)
s = LineSegment(Point(1, 1, 'A'), Point(3, 4, 'B'))
assert s.point_at(Number('0.8')) == Point('2.6', '3.4')
assert s.point_at(2) == Point(5, 7)
assert s.point_at(Number('0.5')) == s.midpoint()
def test_midpoint():
"""Check midpoint is correct."""
s = LineSegment(Point(0, 0, 'A'), Point(1, 1, 'B'))
assert s.midpoint() == Point(Number('0.5'), Number('0.5'))