fix(samples): filter out heartbeat messages from webhook stream UI

[pengying]

Co-Authored-By: Claude Opus 4.6 noreply@anthropic.com

Ignore heartbeat messages in the webhook stream event handler to prevent them from being processed as regular webhook events.

[pengying]

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• fix(samples): filter out heartbeat messages from webhook stream UI #198 👈 (View in Graphite)
• feat(samples): add TypeScript backend using Grid TypeScript SDK #197
• feat: adding kotlin sample #192
• main

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Greptile Summary

This PR filters out heartbeat messages from the SSE stream to prevent them from being displayed as webhook events in the UI. The backend sends data: heartbeat\n\n every 30 seconds to keep the SSE connection alive (index.ts:74), and the frontend now properly ignores these by checking if the raw data equals 'heartbeat' before processing. Additionally, the catch block now silently skips non-JSON messages instead of adding them as raw events.

Changes:

• Added early return for empty or heartbeat messages before JSON parsing
• Removed the catch block logic that was adding unparseable messages as raw events
• Cleaned up error handling to align with the heartbeat filtering approach

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The change is a simple, focused fix that filters heartbeat messages from the UI. The logic is sound: it checks for heartbeat strings before JSON parsing, preventing them from appearing as events. The implementation aligns correctly with the backend's heartbeat sending mechanism (every 30 seconds). No logic errors, security issues, or breaking changes.
• No files require special attention

Important Files Changed

Filename	Overview
samples/frontend/src/components/WebhookStream.tsx	Filters heartbeat messages from SSE stream to prevent display as webhook events

_{Last reviewed commit: 5dc3954}