ystem Stability & Reliability Enhancements

[navin-oss]

Overview

This contribution strengthens backend reliability, real-time communication stability, crisis detection accuracy, API correctness, and frontend resilience through structural refactoring and critical bug fixes.

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🔧 Chat System Improvements

1. Database Schema Enhancement

• Added nickname column to the messages table.
• Ensures historical messages retain sender identity.
• Removes dependency on complex joins for identity resolution.
• Improves long-term data integrity.

2. WebSocket Modernization

• Migrated to WebSocketServer to resolve deprecation issues.
• Ensures compatibility with current standards.

3. Duplicate Connection Prevention

• Refactored connection management using Map<userId, WebSocket>.
• Guarantees one active session per user.
• Prevents memory leaks and inconsistent session states.

4. Reconnection Race Condition Fix

• Fixed issue where rapid reconnection could disconnect the active session.
• Improved lifecycle handling of WebSocket connections.

5. Improved Message Persistence

• Nickname is now saved with each message at creation time.
• Ensures consistency of historical chat records.

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🛑 Crisis Detection Enhancements

6. Severity Evaluation Logic Fix

• Updated keyword scanning to evaluate all severity levels.
• Ensures highest risk level is captured accurately.

7. Improved AI + Keyword Integration

• Refined aggregation logic combining AI-based and keyword-based assessments.
• Increased reliability of final risk classification.

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🌐 API Reliability Improvements

8. Correct HTTP Status Handling (Journal Routes)

• Fixed incorrect responses in PUT and DELETE routes.
• Properly interpreted PostgREST error responses.
• Returns 404 for non-existent resources instead of:
  • 500 (server error)
  • False success responses.
• Improved REST compliance and API predictability.

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🖥 Frontend Stability & Type Safety

9. UI Resilience Improvement

• Added fallback "Anonymous" for messages without nickname.
• Prevents frontend rendering issues.

10. TypeScript Type Fixes

• Resolved HeadersInit typing issues in api.ts.
• Improved compile-time safety and developer experience.

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📈 Overall Impact

• Eliminated WebSocket race conditions.
• Improved concurrency handling.
• Strengthened database schema design.
• Increased crisis detection accuracy.
• Enforced proper REST standards.
• Enhanced frontend stability.
• Improved overall system maintainability.

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🛠 Tech Stack

• Node.js
• WebSocketServer
• TypeScript
• PostgreSQL
• PostgREST
• React

[navin-oss]

i already solve this in pr and this is medium to hard level