test: improve test coverage for usePatientStatus and useQueueSocket hooks (branches & edge cases)

📝 Overview

This MR improves unit test coverage for the custom hooks usePatientStatus.ts and useQueueSocket.ts by covering previously untested branches and edge cases.

The goal is to increase overall coverage to ≥95%, ensuring better reliability of patient status handling and real-time queue updates. This change enhances confidence during refactoring and reduces the risk of runtime issues in asynchronous and socket-based logic.

💡 What does this MR do and why?

The motivation behind this change was insufficient branch coverage in both hooks:

- usePatientStatus.ts: ~77% branch coverage
- useQueueSocket.ts: ~64% branch coverage

Critical logic such as conditional branches, socket events, and cleanup behavior were not fully tested.

Approach:
- Added comprehensive unit tests using Jest and React Testing Library (renderHook)
- Mocked socket connections and API responses
- Explicitly triggered uncovered branches and edge cases
- Tested lifecycle behavior including initialization and cleanup

Trade-offs:
- Increased test complexity and file size, but significantly improved reliability and maintainability


## 🔧 **Changes Made**


- Added unit tests for usePatientStatus.ts and useQueueSocket.ts
- Covered previously uncovered lines:
  - usePatientStatus.ts: 152–153, 163
  - useQueueSocket.ts: 56–57, 114
- Tested conditional branches and edge cases
- Mocked socket.io-client for event handling
- Added tests for:
  - Hook initialization
  - State updates
  - Invalid/edge input handling
  - Socket connection and events
  - Cleanup logic (unsubscribe on unmount)
  - Error handling scenarios
- Improved branch, function, and line coverage to ≥95%


## 🔍 **Technical Details**

Root Cause:
Low branch coverage due to missing test cases for conditional logic, socket lifecycle, and edge cases.

Fix:
- Used renderHook for testing custom hooks
- Used act() for state updates
- Mocked socket connections using jest.mock("socket.io-client")
- Simulated socket events (on, emit, off)
- Verified cleanup using unmount()

Key Areas Covered:
- Conditional branches (if/else, early returns)
- Socket lifecycle (connect → event → cleanup)
- Error scenarios and fallback handling

## 🏷️ **Type of Change**


- [ ] 🐛 Bug fix
- [ ] ✨ New feature
- [ ] 💥 Breaking change
- [ ] 📝 Documentation update
- [ ] 🎨 UI/UX improvement
- [ ] ♻️ Refactor
- [x] ⚡ Performance improvement
- [x] 🧪 Test update
- [ ] 🔧 Configuration change
- [ ] 🚨 Security fix

## 🔗 **Related Issues / References**

      #274 


Below shows the improvement in test coverage for both hooks.

Before	After
Low branch coverage (~77% / ~64%)	Coverage improved to ≥95%
Uncovered conditional logic and edge cases	All branches and edge cases covered
Missing socket lifecycle tests	Full socket lifecycle tested

🧪 How to Set Up and Validate Locally

# 1. Checkout branch
git checkout <branch-name>

# 2. Install dependencies
bun install

# 3. Run tests
npm run test

# 4. Run coverage
npm run test -- --coverage

Expected:

• All tests pass ✅
• Coverage ≥95% for both hooks

---

🧪 Testing Done

- [x] Manual testing completed
- [x] Unit tests added/updated

Test Cases Covered

Scenario	Expected Result	Status
Initialize usePatientStatus hook	Default state set correctly	✅
Update patient status	State updates based on input data	✅
Handle invalid patient data	No crash, fallback handled	✅
Cover conditional branches (152–153)	Branch logic executed	✅
Cover edge case (163)	Expected behavior achieved	✅
Initialize socket connection	Socket connects successfully	✅
Receive queue updates	State updates on socket event	✅
Cover socket branch (56–57)	Branch executed correctly	✅
Cleanup on unmount	Socket listeners removed	✅
Handle socket error (114)	Error handled gracefully	✅

---

⚠️ Known Limitations / Technical Debt

- Tests focus on unit-level coverage; integration tests can be added for full workflow validation
- Socket mocking may not fully replicate real-world network conditions

---

📝 Additional Notes

- This MR does not introduce any functional changes
- Focus is purely on improving test reliability and coverage
- Ensures safer future enhancements for real-time features