fix #1446: monitor dies when exceptions raised before monitor created.

[woolen-sheep]

Summary

• Fix the problem of monitor dies if an exception raised during reconnect before monitor created.
• Add a unit test test_interactions_with_disconnection for Slack server side request to disconnect.

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

• slack_sdk.web.WebClient (sync/async) (Web API client)
• slack_sdk.webhook.WebhookClient (sync/async) (Incoming Webhook, response_url sender)
• slack_sdk.socket_mode (Socket Mode client)
• slack_sdk.signature (Request Signature Verifier)
• slack_sdk.oauth (OAuth Flow Utilities)
• slack_sdk.models (UI component builders)
• slack_sdk.scim (SCIM API client)
• slack_sdk.audit_logs (Audit Logs API client)
• slack_sdk.rtm_v2 (RTM client)
• /docs-src (Documents, have you run ./scripts/docs.sh?)
• /docs-src-v2 (Documents, have you run ./scripts/docs-v2.sh?)
• /tutorial (PythOnBoardingBot tutorial)
• tests/integration_tests (Automated tests for this library)

Requirements (place an x in each [ ])

• 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 python3 -m venv .venv && source .venv/bin/activate && ./scripts/run_validation.sh after making the changes.

[woolen-sheep]

• Fix the problem of monitor dies if an exception raised during reconnect before monitor created.
• Add a unit test test_interactions_with_disconnection for Slack server side request to disconnect.
  • To test server side disconnect and reconnect, the unit test will call client.issue_new_wss_url(), so I had to modify the mocked web server and related tests to return a URL that is able to be used.
  • This test only able to test is disconnect and reconnect working fine so both the fixed version and the old version can pass it. It's hard to mock the behavior of the exception I mentioned in aiohttp based socket_mode failed to reconnect and enter a broken state #1446 and I didn't find a good way... As a result, I did some patch to the client (locally) and run the test (also locally). Only the fixed version can pass the test with patched client. The patch is here: patch client to test the behavior when exceptions happen woolen-sheep/python-slack-sdk#1

cc @hello-ashleyintech , please kindly review this and do necessary tests if you want.

[codecov]

Codecov Report

Attention: 6 lines in your changes are missing coverage. Please review.

Comparison is base (ebdfe45) 85.61% compared to head (a387a74) 85.67%.
Report is 1 commits behind head on main.

Files	Patch %	Lines
slack_sdk/socket_mode/aiohttp/__init__.py	82.85%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1447      +/-   ##
==========================================
+ Coverage   85.61%   85.67%   +0.06%     
==========================================
  Files         111      111              
  Lines       12128    12137       +9     
==========================================
+ Hits        10383    10398      +15     
+ Misses       1745     1739       -6     

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[seratch]

Thank you so much for taking the time to send this PR. I am (and will be for a while) out of the office now, but will check the changes within a few business days.

[seratch]

Thank you so much for improving this! Looks good to me