feat: accept chunks as arguments to chat.{start,append,stop}Stream methods

[zimeg]

Summary

This PR introduces the chunks argument to the following methods:

• chat.startStream
• chat.appendStream
• chat.stopStream

⚠️ This feature is experimental at the moment!

Testing

The following code snippet might be interesting to experiment with:

import time
...

streamer = client.chat_startStream(
    channel=channel_id,
    recipient_team_id=team_id,
    recipient_user_id=user_id,
    thread_ts=thread_ts,
    chunks=[
        MarkdownTextChunk(text="**onwards processing**"),
        TaskUpdateChunk(
            id="12",
            title="counting bytes...",
            status="in_progress",
        ),
    ],
)

time.sleep(4)

client.chat_appendStream(
    channel=channel_id,
    ts=streamer.get("ts"),
    markdown_text="",
    chunks=[
        TaskUpdateChunk(
            id="12",
            title="adding numbers...",
            status="in_progress",
            details="sums have increased",
        )
    ],
)

time.sleep(4)

client.chat_stopStream(
    channel=channel_id,
    ts=streamer.get("ts"),
    chunks=[
        TaskUpdateChunk(
            id="12",
            title="solved equation!",
            status="complete",
            sources=[
                URLSource(
                    url="https://oeis.org",
                    text="The On-Line Encyclopedia of Integer Sequences (OEIS)",
                ),
            ],
        ),
        MarkdownTextChunk(text="that computes."),
    ],
)

Category

• slack_sdk.web.WebClient (sync/async) (Web API client)
• slack_sdk.models (UI component builders)
• /docs (Documents)
• tests/integration_tests (Automated tests for this library)

Notes

• Planning to add tests alongside these methods soon!
• Unsure if these are the best naming for "models" and I'm open to suggestions!

Requirements

• 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.

[codecov]

Codecov Report

❌ Patch coverage is 82.97872% with 16 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.90%. Comparing base (96c0f84) to head (1fb7355).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
slack_sdk/models/messages/chunk.py	77.77%	16 Missing ⚠️

Additional details and impacted files

@@                       Coverage Diff                       @@
##           feat-ai-apps-thinking-steps    #1806      +/-   ##
===============================================================
- Coverage                        83.91%   83.90%   -0.01%     
===============================================================
  Files                              115      116       +1     
  Lines                            13080    13168      +88     
===============================================================
+ Hits                             10976    11049      +73     
- Misses                            2104     2119      +15     

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[srtaalej]

lgtm! except does the helper function not have to change the way it updates the buffer now that we can use chunks instead of markdown?

[zimeg]

@srtaalej Thanks for taking a look! I separated changes to the chat_stream helper in #1809 for more clear review, but some changes might've been better suited for here - perhaps optional markdown text...

[zimeg]

👾 Leaving a few updates from the future! These are refactors made in a "stacked" branch. Please do let me know if rebasing is preferred though-

[zimeg]

📣 note: In 6073ffe of #1819 this is moved into the block elements class because it can be used in standalone messages - not just chunks.

[zimeg]

🧮 note: It's also changed from "URL" to "Url" to match similar elements!

[zimeg]

🪓 note: This is simplified alongside the changes of #1819 as well!