Fix #644 app.message listener does not handle events when a file is attached

[seratch]

This pull request resolves #644

When it comes to the feature parity with bolt-js, we may want to remove the subtype constraints in bolt-python. bolt-js does not check any subtypes when matching message text in app.message listeners: https://github.com/slackapi/bolt-js/blob/%40slack/bolt%403.11.0/src/App.ts#L602-L615

That being said, changing bolt-python app.message listeners to handle other message patterns by Slack product (e.g., channel_join, channel_posting_permissions) could be a breaking change to existing apps. Also, more importantly, passing message_changed and so on would require code changes on the bolt-python user side for sure plus the behavior should not be desired at all.

For this reason, I didn't change the part drastically and went with just adding file_share subtype to the allowed list.

Category (place an x in each of the [ ])

• slack_bolt.App and/or its core components
• slack_bolt.async_app.AsyncApp and/or its core components
• Adapters in slack_bolt.adapter
• Document pages under /docs
• Others

Requirements (place an x in each [ ])

Please read the Contributing guidelines and Code of Conduct before creating this issue or pull request. By submitting, you are agreeing to those rules.

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've run ./scripts/install_all_and_run_tests.sh after making the changes.

[codecov]

Codecov Report

Merging #645 (5a02496) into main (20bfec8) will not change coverage.
The diff coverage is n/a.

❗ Current head 5a02496 differs from pull request most recent head 138abe1. Consider uploading reports for the commit 138abe1 to get more accurate results

@@           Coverage Diff           @@
##             main     #645   +/-   ##
=======================================
  Coverage   92.04%   92.04%           
=======================================
  Files         170      170           
  Lines        5793     5793           
=======================================
  Hits         5332     5332           
  Misses        461      461           

Impacted Files	Coverage Δ
slack_bolt/app/app.py	87.27% <ø> (ø)
slack_bolt/app/async_app.py	94.20% <ø> (ø)

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[filmaj]

Thanks for this change!

Regarding the potential breaking change to line up behaviour with bolt-js, my view on this is that consistency between bolt-js and bolt-python is more a nicety for us as maintainers rather than for bolt users. I think bolt users would probably stay with one language, generally, and therefore not expect identical behaviour if they move to a different language for bolt? What does everyone else think?

If the above assumption is accurate or agreed on by the rest of the team, then releasing a breaking change just to improve maintainers lives seems heavy-handed and should not be done just for that one change. However, if we have other, user-facing breaking changes we would like to land, then adding the subtype matching change in together with other breaking changes in the next major release may make sense.

[celestinojones]

Just wanted to add to the discussion for some context. I can confirm that there are teams who work with a combination of our SDKs across sectors, and one of them noticed the inconsistency first and brought it up to support, so this is in response to user feedback.

[filmaj]

Thank you for that additional context @celestinojones, your input helps make sure we are in line with customer expectations 🙏

[seratch]

@filmaj @celestinojones Thanks for the comments!

As for other subtypes apart from file_share, we may want to revisit in the future if it's worth. However, I think that we should not decide to simply change the app.message listener behavior without any options to opt-in (for existing bolt-python apps). I have to say that the subtypes in message events are tricky in the nature. We can be more careful than usual for the behavior change.

Either way, this file_share subtype pattern is an obvious bug, so that we should fix this as early as possible. Thus, we can merge this PR for the upcoming patch version release now. Thanks for the review and discussion!