def test_invalid_tuple_addition_raises_value_error(self):
vector = Vector(-2, 3, 1)
with pytest.raises(ValueError):
vector.add((1, 2, 3, 4)) # tuple that is not a Point or a Vector
def test_addition_invalid_type_argument_raises_type_error(self):
vector = Vector(-2, 3, 1)
with pytest.raises(TypeError):
# one can not add a scalar to a vector
vector.add(1)
def test_tuple_as_point_addition_results_in_new_tuple(self):
start = (3, -2, 5, 1) # emulates a Point
vector = Vector(-2, 3, 1)
dest = vector.add(start)
assert isinstance(dest, tuple)
assert dest is not start
def test_tuple_as_vector_addition_results_in_new_tuple(self):
v1 = (3, -2, 5, 0) # emulates a Vector
v2 = Vector(-2, 3, 1)
vr = v2.add(v1)
assert isinstance(vr, tuple)
assert vr is not v1
def test_point_addition_results_in_new_point_object(self):
starting_point = Point(3, -2, 5)
vector = Vector(-2, 3, 1)
destination = vector.add(starting_point)
assert isinstance(destination, Point)
assert destination is not starting_point
def test_vector_addition_results_in_new_vector_object(self):
v1 = Vector(2, 3, 1)
v2 = Vector(3, 2, 1)
vr = v1.add(v2)
assert isinstance(vr, Vector)
assert vr is not v1
def test_addition_to_tuple_as_vector(self):
v1 = Vector(2, 3, 1)
v2 = (3, 2, 1, 0)
vr = v1.add(v2)
# a vector added to a vector results in a resulting vector (w=0)
assert vr == (5, 5, 2, 0)
def test_addition_to_vector_object(self):
v1 = Vector(2, 3, 1)
v2 = Vector(3, 2, 1)
vr = v1.add(v2)
# a vector added to a vector results in a resulting vector (w=0)
assert vr.to_tuple() == (5, 5, 2, 0)
def test_addition_to_point_object(self):
point = Point(3, -2, 5)
vector = Vector(-2, 3, 1)
destination = vector.add(point)
# a point added to a vector results in a translated point (w=1)
assert destination.to_tuple() == (1, 1, 6, 1)
