def test_invalid_op():
crdt = CRDT()
operation = Operation(ts=datetime.utcnow().timestamp(), key='a', value=1, op=-1)
# Append should fail if the operation is invalid
try:
crdt.append(operation)
assert False
except AssertionError as e:
assert str(e) == INVALID_OP
def test_out_of_order_append():
crdt = CRDT()
crdt.add('a', 1)
inserted = crdt.log[-1]
operation = Operation(ts=inserted.ts - 1, key=inserted.key, value=inserted.value, op=inserted.op)
# Append should fail if the timestamp of the operation is earlier than the last inserted operation
try:
crdt.append(operation)
assert False
except AssertionError as e:
assert str(e) == INVALID_TS
