def test_last_state(self):
"""
Tests that Set=low & Reset=Low provides the previous state
"""
set_node = Node(State.low, name="Set")
reset_node = Node(State.high, name="Reset")
latch = SRNandLatch([set_node, reset_node])
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.high
assert out_nodes["QBar"] == State.low
set_node.state = State.high
reset_node.state = State.high
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.high
assert out_nodes["QBar"] == State.low
set_node.state = State.high
reset_node.state = State.low
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.low
assert out_nodes["QBar"] == State.high
set_node.state = State.high
reset_node.state = State.high
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.low
assert out_nodes["QBar"] == State.high
def test_no_change_state_high_output(self):
d = Node(State.high, name="D")
clk = Node(State.high, name="Clk")
ff = DTypeFlipFlop([d, clk])
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
d.state = State.low
clk.state = State.low
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
d.state = State.high
clk.state = State.low
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
d.state = State.low
clk.state = State.low
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
def test_get_object_by_name_success(self):
node1 = Node(name="set")
node2 = Node(name="Reset")
node3 = Node(name="3")
nodes = NodeList([node1, node2, node3])
assert nodes.get_object_by_name("set") == node1
assert nodes.get_object_by_name("Reset") == node2
assert nodes.get_object_by_name("3") == node3
def test_get_object_by_name_fail_case_sensitive(self):
node1 = Node(name="set")
node2 = Node(name="2")
node3 = Node(name="3")
nodes = NodeList([node1, node2, node3])
with pytest.raises(ValueError) as ex:
nodes.get_object_by_name("Set")
assert str(ex.value
) == f"Node Set not found. Valid node names are (set, 2, 3)"
def test_get_object_by_name_fails(self):
node1 = Node(name="1")
node2 = Node(name="2")
node3 = Node(name="3")
nodes = NodeList([node1, node2, node3])
with pytest.raises(ValueError) as ex:
nodes.get_object_by_name("4")
assert str(
ex.value) == f"Node 4 not found. Valid node names are (1, 2, 3)"
def test_str(self):
a = OneOutputComponent(
inputs=[Node(name="node1"),
Node(name="node2", state=State.high)],
name="my component",
)
a._outputs = NodeList([Node(name="output")])
assert (
str(a) ==
"my component: (node1: State.low, node2: State.high) -> (output: State.low)"
)
def test_str(self):
a = MultipleOutputComponent(
inputs=[Node(name="node1"),
Node(name="node2", state=State.high)],
name="my component",
)
a._outputs = NodeList(
[Node(name="output1"),
Node(name="output2", state=State.high)])
assert str(a) == (
"my component: (node1: State.low, node2: State.high) -> (output1: State.low, output2: State.high)"
)
def test_basic(self):
d = Node(State.low, name="D")
clk = Node(State.high, name="Clk")
ff = DTypeFlipFlop([d, clk])
ff.calculate()
assert ff.outputs["Q"].state == State.low
assert ff.outputs["QBar"].state == State.high
d.state = State.high
clk.state = State.high
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
def test_validation_expected_names_success(self):
nodes = NodeList([Node(name="1"), Node(name="2")])
nodes.validate("element", expected_names=["1", "2"])
def test_validation_maximum_fails(self):
nodes = NodeList([Node(name="1"), Node(name="2")])
with pytest.raises(ValueError) as ex:
nodes.validate("element", max_length=1)
assert str(ex.value) == f"element must have a maximum of 1 inputs."
def test_validation_maximum_success(self):
nodes = NodeList([Node(name="1"), Node(name="2")])
nodes.validate("element", max_length=2)
def test_name(self):
c = self.component([Node(State.low), Node(State.low)], name="testname")
assert c.name == "testname"
def test_one_input_fails_set_inputs(self):
with pytest.raises(ValueError) as ex:
c = self.component(name="testname")
c.inputs = [Node(State.low)]
assert (str(ex.value) ==
f"{self.component.__name__} must have two or more inputs.")
def test_names(self):
c = self.component([Node(State.low)], name="testname")
assert c.name == "testname"
assert c.outputs[0].name == "testname_out"
def test_not_gate(self, ina, result):
a = Node(ina)
b = self.component([a])
assert b.calculate()[0].state == result
assert b.outputs[0].state == result
def test_xnor_gate(self, ina, inb, inc, result):
c = self.component([Node(ina), Node(inb), Node(inc)])
assert c.calculate()[0].state == result
assert c.outputs[0].state == result
def test_comparing_nodes_with_states(self):
a = Node(state=State.high)
assert a == State.high
def test_validation_expected_names_missing(self):
nodes = NodeList([Node(name="2")])
with pytest.raises(ValueError) as ex:
nodes.validate("element", expected_names=["2", "3"])
assert str(ex.value) == f"The following node names were missing: 3"
def test_gate(self, s, r, q, qbar):
latch = SRNandLatch([Node(s, name="Set"), Node(r, name="Reset")])
out_nodes = latch.calculate()
assert [i.state for i in out_nodes] == [q, qbar], latch
def test_too_many_inputs(self):
with pytest.raises(ValueError) as ex:
self.component([Node(), Node()])
assert str(ex.value) == "A not gate can only have one input."
def test_name_null(self):
c = self.component([Node(State.low), Node(State.low)], name=None)
assert c.name == self.component.__name__
def test_str(self):
a = Node(name="hello world", state=State.high)
assert str(a) == f"hello world: State.high"
def test_str(self):
a = NodeList([Node(name="node", state=State.high)])
assert str(a) == "[node: State.high]"
