def test_body_from_parameters_raises_valueerror_if_k_units_not_correct():
wrong_k = 4902.8 * u.kg
_name = _symbol = ""
_R = 0
with pytest.raises(u.UnitsError) as excinfo:
Body.from_parameters(None, wrong_k, _name, _symbol, _R)
assert (
"UnitsError: Argument 'k' to function 'from_parameters' must be in units convertible to 'km3 / s2'."
in excinfo.exconly())
def test_body_from_parameters_returns_body_object():
k = 1.26712763e17 * u.m**3 / u.s**2
R = 71492000 * u.m
_name = _symbol = "jupiter"
jupiter = Body.from_parameters(Sun, k, _name, _symbol, Jupiter.R)
assert jupiter.k == k
assert jupiter.R == R
