def test_invalid_amount_of_operands(self):
with pytest.raises(TypeError) as e:
node = CombinationNode()
node.append(PrimitiveNode(add))
node.eval()
assert "combination needs to have at least two operands" in str(e.value)
def test_invalid_operator(self):
with pytest.raises(TypeError) as e:
node = CombinationNode()
for i in range(3):
node.append(PrimitiveNode(1))
node.eval()
assert "operator not found" in str(e.value)
class RootNode(Node):
def __init__(self):
self._node = CombinationNode()
def eval(self):
return self._node.eval()
def append(self, node):
self._node = node
def test_eval_without_nodes_should_return_none(self):
node = CombinationNode()
assert node.eval() is None
def test_eval_two_operands(self):
node = CombinationNode()
node.append(PrimitiveNode(add))
node.append(PrimitiveNode(1))
node.append(PrimitiveNode(2))
assert 3 == node.eval()