Deprecate releasing a channel that isn't detached (RTS4b)

[SimonWoolf]

Implements RTS4b from spec 6.3.0 (ably/specification#557). Calling channels.release(name) on a realtime channel that isn't INITIALIZED, DETACHED or FAILED still detaches it and then removes it. It now also logs a warning that this is deprecated and will be an error in the next major version, and that you should call channel.detach() and wait for it to complete before releasing. The release docstring is updated to match.

Tests check that releasing an attached channel logs the warning and that releasing a detached channel doesn't.

The next-major change is in #2315. Reference ably-js PRs: ably/ably-pubsub-js#2322 (deprecation) and ably/ably-pubsub-js#2323 (next major).

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Summary by CodeRabbit

• Deprecations
  • Releasing a channel outside the initialized, detached, or failed states is deprecated and will become an error in the next major version. Releasing an attached channel still detaches and removes it, with a warning.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Organization UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 79c92433-aa4d-4379-870a-64599f119881

📥 Commits

Reviewing files that changed from the base of the PR and between 2072e0c and 4f7c90b.

📒 Files selected for processing (3)

• Source/ARTRealtimeChannels.m
• Source/include/Ably/ARTChannels.h
• Test/AblyTests/Tests/RealtimeClientChannelsTests.swift

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Walkthrough

release now logs a deprecation warning when called for a channel outside the Initialized, Detached, or Failed states. Tests verify release behavior and warning output for attached and detached channels.

Changes

Channel release behavior

Layer / File(s)	Summary
Release state handling and warning Source/ARTRealtimeChannels.m, Source/include/Ably/ARTChannels.h, Test/AblyTests/Tests/RealtimeClientChannelsTests.swift	The documentation says release in states other than Initialized, Detached, or Failed is deprecated and will become an error in the next major version. The implementation logs a warning before detaching in those states. Tests verify that releasing an attached channel logs one warning and removes it, while releasing a detached channel logs no warning and removes it.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Other

Merge Risk: ⚪ Minimal · up to 4f7c9

No merge-blocking issue is identified; the release deprecation warning is ready for normal merge checks.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 2 files. (1 skipped: 1…	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly summarizes the main change: it deprecates releasing a channel that is not detached. The RTS4b reference adds useful specification context.

Full details: Docstring Coverage

Explanation

Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 2 files. (1 skipped: 1 unsupported.)

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_{A rabbit checks the channel state,
Then logs a note before the gate.
Attached hops to detached ground,
Detached leaves without a sound.
The channel exits, tests look through,
And carrots wait in queues anew.}

_{Comment @coderabbitai help to get the list of available commands.}