def test_reducer_given_set_value_action_adds_key_value(self):
action = db.set_value("name", "value")
state = {"previous": "constant"}
result = db.reducer(state, action)
expect = {
"previous": "constant",
"name": "value"
}
self.assertEqual(expect, result)
def test_reducer_immutable_state():
state = {"pressure": 1000}
next_state = db.reducer(state, db.set_value("pressure", 950))
assert state["pressure"] == 1000
assert next_state["pressure"] == 950
def test_reducer_immutable_state():
"""Ensure copy.deepcopy is used to create a new state"""
previous_state = {"key": ["value"]}
next_state = db.reducer(previous_state, {"kind": "ANY"})
previous_state["key"].append("extra")
assert next_state["key"] == ["value"]