[SimonWoolf]

Implements RTS4c–e from spec 6.3.0 (ably/specification#557) for the next major version.

Breaking change: RealtimeChannels.release(name) now returns Future<void>. A realtime channel can only be released when it is INITIALIZED, DETACHED or FAILED. Releasing it in any other state no longer detaches it implicitly. Instead, the future completes with an AblyException (code 90011, statusCode 400) and the channel stays in the collection. Releasing a name that doesn't exist is a no-op.

Migration: await channel.detach(); and then await realtime.channels.release(name);. This is documented in UPDATING.md.

Implementation:

• release() now awaits the platform call and only drops the Dart-side channel once the platform release succeeds. Previously the platform call was not awaited, so any error was lost and the Dart and platform channel collections diverged.
• The state check is done by the platform SDKs, because RealtimeChannel.state on the Dart side can lag behind the platform channel.

Still to do: the Android and iOS handlers for releaseRealtimeChannel must pass the native release error back (Android: catch AblyException and call handleAblyException; iOS: return a FlutterError with the ARTErrorInfo). This depends on the ably-java and ably-cocoa next-major releases that implement RTS4e, which don't exist yet. With the current native pins (ably-android 1.6.0, Ably 1.2.53) release never fails.

The current-major docs change is in #609. Reference ably-js PRs: ably/ably-pubsub-js#2322 (deprecation) and ably/ably-pubsub-js#2323 (next major).

🤖 Generated with Claude Code

Summary by CodeRabbit

• Behavior Changes
  • Channel release now completes asynchronously. Channels can be released only when initialized, detached, or failed; release attempts in other states return an error and leave the channel unreleased. Detach an attached channel before releasing it.
  • Releasing a channel that does not exist completes without error.
• Documentation
  • Updated the v1.2.x migration guide and API documentation with channel release behavior and state requirements.

[coderabbitai]

Walkthrough

RealtimeChannels.release() now returns a future and awaits the platform release call. The docs describe permitted states and error behavior. The example and tests now await release and cover successful release, nonexistent channels, and platform errors.

Changes

Realtime channel release

Layer / File(s)	Summary
Release API and state contract lib/src/common/src/channels.dart, lib/src/platform/src/realtime/realtime_channels.dart, UPDATING.md	release() now returns Future<void> and awaits the platform invocation. The docs describe permitted states, the error for other states, and release of nonexistent channels. The migration guide says to detach an attached channel before releasing it.
Release usage and validation example/lib/ui/realtime_sliver.dart, test/mock_method_call_manager.dart, test/realtime/channels_test.dart	The example waits for detach and release before retrieving the channel. The mock can return a configured platform error. Tests check successful release, nonexistent channels, and an error mapped to AblyException code 90011 and status 400; the channel remains the same instance after failure.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~12 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant RealtimeSliver
  participant RealtimeChannel
  participant RealtimeChannels
  participant PlatformSDK
  RealtimeSliver->>RealtimeChannel: detach
  RealtimeChannel-->>RealtimeSliver: detach completes
  RealtimeSliver->>RealtimeChannels: release channel
  RealtimeChannels->>PlatformSDK: invoke platform release
  PlatformSDK-->>RealtimeChannels: release result
  RealtimeChannels-->>RealtimeSliver: release completes
  RealtimeSliver->>RealtimeChannels: retrieve channel

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Suggested reviewers: ttypic

Merge Risk: 🟡 Moderate · up to 60fa9

The documentation and API now promise that releasing an attached channel fails with error 90011 and keeps the channel. With the current native SDK versions, release still succeeds silently on both Android and iOS, and on Android a native exception can leave the call hanging. Apps that follow or test against the documented behavior will see different results. Either resolve this before merging or explicitly accept it pending the SDK upgrades.

Pre-merge checks · 5

Passed checks (5 passed)

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main changes: making RealtimeChannels.release() asynchronous and surfacing platform errors.
Docstring Coverage		No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
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.

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_{A rabbit waits while channels part,
Then release completes before the start.
The states are clear, the errors known,
A failed release leaves the channel shown.
Hop, hop—the tests confirm the flow.}

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

[coderabbitai]

Actionable comments posted: 1

---

• 🪄 Fix CodeRabbit comments on this PR

🤖 Prompt to fix review comments

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Inline comments:
Review comments at @lib/src/platform/src/realtime/realtime_channels.dart:
- Line 33: Update RealtimeChannels.release and the native release handlers to
propagate SDK release failures as Flutter errors, preserving error 90011 for an
attached channel so Dart retains the channel; use SDK versions whose release
APIs enforce this state check.

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📥 Commits

Reviewing files that changed from the base of the PR and between ea51456 and 60fa9cf.

📒 Files selected for processing (6)

• UPDATING.md
• example/lib/ui/realtime_sliver.dart
• lib/src/common/src/channels.dart
• lib/src/platform/src/realtime/realtime_channels.dart
• test/mock_method_call_manager.dart
• test/realtime/channels_test.dart

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[ttypic]

LGTM