Two findings from Copilot's review on #15464, both addressed:
1. ``event.get("thread_ts")`` truthy vs
``event_thread_ts != ts``: the new channel branch treated ANY
truthy ``thread_ts`` as a real thread reply, but three lines below
``is_thread_reply`` is defined with the stricter
``event_thread_ts and event_thread_ts != ts`` invariant. If Slack
ever ships a payload where ``thread_ts == ts`` on a thread root,
the stricter check would treat it as a top-level message for the
``is_thread_reply`` path but as a thread reply for session keying
— divergent behaviour. Aligned this branch to the same
``and event_thread_ts_raw != ts`` invariant.
2. ``test_top_level_reply_to_id_stays_none_when_shared`` docstring
had the ternary logic backwards ("None != ts → reply_to_message_id
IS set"). The code reads
``reply_to_message_id = thread_ts if thread_ts != ts else None`` —
with ``thread_ts = None``, the condition is True so the expression
evaluates to ``thread_ts`` itself (None), meaning the reply stays
un-threaded. The test asserted the correct end-state; only the
explanatory docstring was wrong. Rewrote the docstring to match
the actual code flow, with the note that Copilot caught the
reversal.
7/7 tests still pass. No behaviour change for the existing
test_thread_reply_scopes_by_thread_even_when_shared case because
``event_thread_ts_raw = "1700000000.000000"`` and ``ts =
"1700000000.000005"`` are distinct — the new
``!= ts`` guard is a no-op there.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Brian D. Evans
ab0a6270c3