如何在discord.py中测试事件

import pytest
from discord.ext import commands
from unittest.mock import MagicMock

bot = commands.Bot(command_prefix='!')

@bot.event
async def on_ready():
    print(f'Logged in as {bot.user}')

@bot.event
async def on_message(message):
    if message.content == '!hello':
        await message.channel.send('Hello!')

@pytest.mark.asyncio
async def test_on_ready():
    bot.user = MagicMock()
    await on_ready()
    bot.user.assert_called_once()

@pytest.mark.asyncio
async def test_on_message():
    message = MagicMock()
    message.content = '!hello'
    message.channel.send = MagicMock()
    await on_message(message)
    message.channel.send.assert_called_once_with('Hello!')