def test_truncate_equivalent_to_scale(x: Vector, max_length: float):
"""Vector.scale_to and truncate are equivalent when max_length <= x.length"""
assume(max_length <= x.length)
note(f"x.length = {x.length}")
if max_length > 0:
note(f"x.length = {x.length / max_length} * max_length")
scale: Union[Vector, Type[Exception]]
truncate: Union[Vector, Type[Exception]]
try:
truncate = x.truncate(max_length)
except Exception as e:
truncate = type(e)
try:
scale = x.scale_to(max_length)
except Exception as e:
event(f"Exception {type(e).__name__} thrown")
scale = type(e)
if isinstance(scale, Vector) and x.length == max_length:
# Permit some edge-case where truncation and scaling aren't equivalent
assert isinstance(truncate, Vector)
assert scale.isclose(truncate, abs_tol=0, rel_tol=1e-12)
else:
assert scale == truncate
def test_scale_negative_length(v: Vector, length: float):
"""Test that Vector.scale_to raises ValueError on negative lengths."""
assume(length < 0)
with raises(ValueError):
v.scale_to(length)
def test_scale_aligned(x: Vector, length: float):
"""Test that x.scale_to(length) is aligned with x."""
assume(length > 0 and x)
assert angle_isclose(x.scale_to(length).angle(x), 0)
def test_scale_to_length(x: Vector, length: float):
"""Test that the length of x.scale_to(length) is length with x non-null."""
assume(x)
assert isclose(x.scale_to(length).length, length)
