How to Mock RabbitMQ Ack Nack Requeue in Python

import json
from collections import deque


class MockChannel:
    def __init__(self):
        self.acked = []
        self.nacked = []
        self.requeued = []

    def basic_ack(self, delivery_tag):
        self.acked.append(delivery_tag)

    def basic_nack(self, delivery_tag, requeue=False):
        self.nacked.append({"tag": delivery_tag, "requeue": requeue})
        if requeue:
            self.requeued.append(delivery_tag)


class MockConsumer:
    def __init__(self, messages):
        self.channel = MockChannel()
        self.message_queue = deque(messages)
        self.delivery_tag_counter = 0

    def process_next(self):
        if not self.message_queue:
            return None
        message = self.message_queue.popleft()
        self.delivery_tag_counter += 1
        tag = self.delivery_tag_counter
        payload = json.loads(message)
        if payload.get("valid"):
            self.channel.basic_ack(tag)
        else:
            self.channel.basic_nack(tag, requeue=True)
        return payload


if __name__ == "__main__":
    messages = [
        '{"id": 1, "valid": true}',
        '{"id": 2, "valid": false}',
        '{"id": 3, "valid": true}',
    ]
    consumer = MockConsumer(messages)
    while consumer.process_next() is not None:
        pass

    print("Acked:", consumer.channel.acked)
    print("Nacked:", consumer.channel.nacked)
    print("Requeued:", consumer.channel.requeued)