Unify MessageComposer state and expose read-only StateFlows on ViewModels

[andremion]

Goal

Stop duplicating composer UI in extra flows; expose StateFlow only so state is read through MessageComposerState (and setMessageInput / actions) instead of mutable flows.

Implementation

• MessageComposerController: one _state; removed parallel flows (cooldownTimer, suggestions, messageMode, lastActiveAction, public ownCapabilities, etc.); _messageInput / _messageActions with public StateFlow.
• MessageComposerViewModel (Compose + XML): dropped delegating properties; messageInput is StateFlow. Call sites/tests/API dumps updated.
  Breaking: use messageComposerState for those fields; don’t assign messageInput.value — use setMessageInput.

🎨 UI Changes

No intentional visual change.

Testing

• Type, send, cooldown (if slow mode).
• / commands and mention @ suggestions.
• Thread: enter, reply, leave thread; attachment picker height.
• Reply/edit dismiss.
• Run Compose + UI Components samples.

Summary by CodeRabbit

Release Notes

• Refactor
  • Consolidated message composer state management into a single unified state object for improved clarity and consistency.
  • Made message input property read-only to prevent unintended mutations.
  • Removed individual state accessor methods from the public API; state access now routes through the centralized composer state object.

[github-actions]

PR checklist ✅

All required conditions are satisfied:

• Title length is OK (or ignored by label).
• At least one pr: label exists.
• Sections ### Goal, ### Implementation, and ### Testing are filled.

🎉 Great job! This PR is ready for review.

[github-actions]

SDK Size Comparison 📏

SDK	Before	After	Difference	Status
stream-chat-android-client	5.25 MB	5.68 MB	0.43 MB	🟡
stream-chat-android-ui-components	10.60 MB	10.98 MB	0.38 MB	🟡
stream-chat-android-compose	12.81 MB	12.08 MB	-0.73 MB	🚀

[coderabbitai]

Walkthrough

This PR refactors the message composer architecture by consolidating multiple public mutable state flows (cooldown timer, validation errors, suggestions, message mode, capabilities, and actions) into a single read-only messageComposerState holder, making direct flow access internal, converting messageInput to read-only, and updating all dependent code to reference the consolidated state.

Changes

Cohort / File(s)	Summary
Message Composer ViewModel API (Compose) stream-chat-android-compose/api/stream-chat-android-compose.api	Removed 7 public getter methods for individual flows; changed getMessageInput() return type from MutableStateFlow to StateFlow.
Message Composer ViewModel Implementation (Compose) stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/viewmodel/messages/MessageComposerViewModel.kt	Removed public properties: cooldownTimer, validationErrors, mentionSuggestions, commandSuggestions, linkPreviews, messageMode, lastActiveAction, ownCapabilities; changed messageInput from MutableStateFlow<MessageInput> to StateFlow<MessageInput>; removed related imports.
Message Composer ViewModel API (UI Components) stream-chat-android-ui-components/api/stream-chat-android-ui-components.api	Removed 7 public getter methods; updated getMessageInput() return type from MutableStateFlow to StateFlow.
Message Composer ViewModel Implementation (UI Components) stream-chat-android-ui-components/src/main/kotlin/io/getstream/chat/android/ui/viewmodel/messages/MessageComposerViewModel.kt	Removed public properties: cooldownTimer, validationErrors, mentionSuggestions, commandSuggestions, messageMode, lastActiveAction, ownCapabilities; changed messageInput to StateFlow<MessageInput>.
Message Composer Controller stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/feature/messages/composer/MessageComposerController.kt	Converted state, messageInput, messageActions to private backing (_state, _messageInput, _messageActions) with read-only StateFlow exposure; removed public cooldownTimer, validationErrors, mentionSuggestions, commandSuggestions, linkPreviews, messageMode flows; refactored internal logic to read/write through consolidated state; updated setMessageMode implementation with new draft save/fetch orchestration.
Attachment Picker Menu stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/messages/attachments/AttachmentPickerMenu.kt	Changed messageMode source from direct composerViewModel.messageMode collection to composerViewModel.messageComposerState.messageMode.
Chat Fragment (Sample App) stream-chat-android-ui-components-sample/src/main/kotlin/io/getstream/chat/ui/sample/feature/chat/ChatFragment.kt	Consolidated two separate lifecycle-aware collectors (messageMode and lastActiveAction) into single collector of messageComposerState; derived both values from consolidated state.
Message Composer ViewModel Tests (Compose) stream-chat-android-compose/src/test/kotlin/io/getstream/chat/android/compose/viewmodel/messages/MessageComposerViewModelTest.kt	Removed assertions on viewModel.messageMode, viewModel.ownCapabilities, viewModel.commandSuggestions.size, viewModel.mentionSuggestions.size; updated to access via messageComposerState.value; updated suggestion selections to use consolidated state source.
Message Composer ViewModel Tests (UI Components) stream-chat-android-ui-components/src/test/kotlin/io/getstream/chat/android/ui/viewmodels/messages/MessageComposerViewModelTest.kt	Removed direct assertions on messageMode, commandSuggestions, mentionSuggestions, ownCapabilities; updated to validate via messageComposerState and pass suggestions from consolidated state into selection methods.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

🐰 Bouncing with joy through refactored code
Eight scattered flows now dance as one,
Where once there flowed a tangled road,
The state consolidated—elegantly done! ✨
No more public leaks, just clean design,
The composer now shines, oh so fine! 🌟

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 43.14% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main goal: unifying MessageComposer state and converting public flows to read-only StateFlows on ViewModels.
Description check	✅ Passed	The description includes Goal, Implementation, UI Changes, and Testing sections matching the template structure, but omits the contributor/reviewer checklists and GIF.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch remove-derived-state-in-message-composer

📝 Coding Plan

• Generate coding plan for human review comments

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[coderabbitai]

Actionable comments posted: 3

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@stream-chat-android-compose/api/stream-chat-android-compose.api`:
- Line 7082: Update the UNRELEASED CHANGELOG under the
stream-chat-android-compose → Changed section to document that getMessageInput()
now returns a read-only StateFlow (not MutableStateFlow), which prevents direct
assignment via messageInput.value; note the migration path instructing consumers
to call the provided setMessageInput(...) API instead of mutating
messageInput.value and mention this is an intentional API shape change for
immutability.

In
`@stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/feature/messages/composer/MessageComposerController.kt`:
- Around line 927-928: The controller is exposing its internal MutableSet
(selectedMentions) into public state, causing later mutations (+= and clear())
to break snapshot immutability; change the _state.update call in
MessageComposerController to publish an immutable copy (e.g.,
selectedMentions.toSet() or HashSet(selectedMentions)) instead of the live
MutableSet, and when filterMentions() clears the backing set call _state.update
{ it.copy(selectedMentions = emptySet()) } (or publish an explicit empty
snapshot) so consumers never observe the mutable backing instance.
- Around line 533-540: The current setMessageMode publishes the new mode only
after saveDraftMessage(prev) which can suspend, causing races; change the order
so setMessageMode first updates/publishes the new mode via _state.update {
it.copy(messageMode = messageMode) } (while still capturing previousMode for the
draft), then call saveDraftMessage(previousMode) and finally
fetchDraftMessage(messageMode); update the implementation in setMessageMode (and
keep isSameMessageMode check) to ensure the new mode is visible immediately and
avoid stale reads from concurrent setMessageMode calls.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 89036ccf-92f2-472f-8a2f-017b0bfa8566

📥 Commits

Reviewing files that changed from the base of the PR and between 65d5819 and 7067046.

📒 Files selected for processing (9)

• stream-chat-android-compose/api/stream-chat-android-compose.api
• stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/messages/attachments/AttachmentPickerMenu.kt
• stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/viewmodel/messages/MessageComposerViewModel.kt
• stream-chat-android-compose/src/test/kotlin/io/getstream/chat/android/compose/viewmodel/messages/MessageComposerViewModelTest.kt
• stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/feature/messages/composer/MessageComposerController.kt
• stream-chat-android-ui-components-sample/src/main/kotlin/io/getstream/chat/ui/sample/feature/chat/ChatFragment.kt
• stream-chat-android-ui-components/api/stream-chat-android-ui-components.api
• stream-chat-android-ui-components/src/main/kotlin/io/getstream/chat/android/ui/viewmodel/messages/MessageComposerViewModel.kt
• stream-chat-android-ui-components/src/test/kotlin/io/getstream/chat/android/ui/viewmodels/messages/MessageComposerViewModelTest.kt

[sonarqubecloud]

Quality Gate failed

Failed conditions
70.2% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud