refactor: introduce WithComponents context provider

[oliverlaz]

🎯 Goal

Replace the prop-drilling of 120+ component overrides with a single WithComponents context provider. This eliminates massive boilerplate across Channel, ChannelList, and all consumer components.

Before:

<Channel Message={MyMessage} SendButton={MySendButton} Reply={MyReply} channel={channel}>

After:

<WithComponents overrides={{ Message: MyMessage, SendButton: MySendButton, Reply: MyReply }}>
  <Channel channel={channel}>
</WithComponents>

🛠 Implementation details

Design principle

All components are read from useComponentsContext(). All other contexts only provide data + APIs — never components.

New ComponentsContext

• WithComponents provider — nestable, inner overrides win. Uses overrides prop (aligned with stream-chat-react)
• useComponentsContext() hook — returns all components with defaults filled in
• ComponentOverrides type — auto-derived from DEFAULT_COMPONENTS map (Partial<typeof DEFAULT_COMPONENTS>)
• defaultComponents.ts — single source of truth for all ~120 default component mappings (lazy-loaded to avoid circular deps)
• Adding a new overridable component only requires editing defaultComponents.ts — the type is derived automatically

What changed

• Stripped component keys from MessagesContextValue, InputMessageInputContextValue, ChannelContextValue, ChannelsContextValue, AttachmentPickerContextValue, ThreadsContextValue, ImageGalleryContextValue — these now only carry data + APIs
• Simplified useCreate*Context hooks — no longer receive or forward component params
• Simplified Channel.tsx — removed ~90 component imports, prop defaults, and forwarding lines
• Simplified ChannelList.tsx — removed ~19 component props
• Updated ~80 consumer files — switched from old context hooks to useComponentsContext() for component reads
• Removed component override props from ALL individual components (Chat, Thread, ThreadList, Poll, ChannelPreview, ImageGallery, etc.)
• No component accepts component overrides as props anymore — everything goes through WithComponents
• ComponentsContext.tsx reduced from ~350 lines to ~55 lines — type is derived from defaults, no manual type maintenance
• Updated all 3 example apps (SampleApp, ExpoMessaging, TypeScriptMessaging) to use WithComponents

Net result

• 90+ files changed, net -2500+ lines removed
• Each component override name went from being listed 4 times to 0 in the forwarding pipeline
• One place to override components: <WithComponents overrides={{ ... }}>
• One place to read components: useComponentsContext()
• One place to add new overridable components: defaultComponents.ts

BREAKING CHANGE

• Component override props removed from all SDK components — <Channel Message={X}>, <ChannelList Preview={X}>, <Thread MessageComposer={X}>, etc. no longer accept component overrides as props. Use <WithComponents overrides={{ Message: X }}> instead.
• Component keys removed from context value types — MessagesContextValue, InputMessageInputContextValue, ChannelContextValue, ChannelsContextValue, AttachmentPickerContextValue, ThreadsContextValue, ImageGalleryContextValue no longer include component-type keys. Use useComponentsContext() to read component overrides.
• List prop removed from ChannelList — use custom EmptyStateIndicator override or wrap ChannelListView directly.
• LoadingIndicator prop removed from Chat — use <WithComponents overrides={{ ChatLoadingIndicator: X }}>.

🎨 UI Changes

No visual changes — this is a pure structural refactor.

🧪 Testing

• yarn build — 0 type errors
• yarn lint — passes clean (0 warnings, 0 errors)
• yarn test:unit — 91/92 suites pass; 1 pre-existing timeout failure in offline-support that also fails on develop
• New test: defaultComponents.test.ts verifies all default component mappings are defined and optional keys are explicitly listed
• Updated test files to use <WithComponents overrides={...}> wrapper instead of removed component override props

☑️ Checklist

• I have signed the Stream CLA (required)
• PR targets the develop branch
• Documentation is updated
• New code is tested in main example apps, including all possible scenarios
  • SampleApp iOS and Android
  • Expo iOS and Android

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
js_bundle_size	351 KB	351 KB	+301 B	🟡