Test Async callback using Contracts

[Ehsan-U]

Is there a way to test an async callback using Scrapy contracts? Based on the error message, it seems like there's no support for that. It would be great to have this feature, or maybe I'm missing something. Should I even use contracts in such cases, or is there a better alternative?

----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/ehsan/projects/upwork/karim/maryland-scraper/.venv/lib/python3.12/site-packages/scrapy/contracts/__init__.py", line 183, in cb_wrapper
    output = cb(response, **cb_kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ehsan/projects/upwork/karim/maryland-scraper/.venv/lib/python3.12/site-packages/scrapy/contracts/__init__.py", line 70, in wrapper
    raise TypeError("Contracts don't support async callbacks")
TypeError: Contracts don't support async callbacks

[elacuesta]

As you can see from the traceback, the lack of support for async callbacks comes from upstream Scrapy. I'd suggest to open an issue in Scrapy itself if you'd like to start a conversation about it.

Please see #262 for a similar discussion.