Refactor badge module

[shamoo53]

🔄 Refactor: Modularize Badge Module into Provider-Based Architecture
🎯 Objective
Refactored the BadgeModule to follow NestJS best practices by separating all business logic into dedicated provider classes, enforcing Single Responsibility Principle and improving testability, maintainability, and scalability.

🧱 Summary of Changes

1. Responsibility Breakdown from BadgeService
   Analyzed BadgeService and extracted the following responsibilities:

seedDefaultBadges

determineBadgeForRank

autoAssignBadges

getBadgeByRank

remove, update, create

findOne, findAllActive, findAll

2. Introduced Dedicated Providers
   Created provider classes in src/badge/providers/, each responsible for a single concern:

SeedDefaultBadgesService

DetermineBadgeForRankService

AutoAssignBadgesService

GetBadgeByRankService

RemoveBadgeService

UpdateBadgeService

CreateBadgeService

FindOneBadgeService

FindAllActiveBadgesService

FindAllBadgesService

Each class encapsulates its logic and repository interactions, enabling focused testing and isolation.

3. Refactored BadgeService
   Stripped all logic from BadgeService

Transformed it into a delegator that invokes methods on the appropriate provider

Injected all new providers through the constructor

4. Module Updates
   Registered all provider classes in badge.module.ts

Ensured smooth dependency injection setup

Preserved existing exports for compatibility

5. Unit Test Refactor
   Updated badge.service.spec.ts to mock and test provider-based interactions

Resolved TypeScript typing issues in DTOs and mocks

Ensured all unit tests continue to pass with full coverage

6. Controller Validation
   Confirmed BadgeController requires no changes

BadgeService remains its single point of contact

Controller continues to delegate correctly, without internal business logic

✅ Key Benefits
✅ Separation of Concerns — Each logic path is isolated in its own class

✅ Improved Testability — Fine-grained unit tests possible for each provider

✅ Easier Maintenance — Modifying badge logic is now low-risk and isolated

✅ Clean Architecture — Strong adherence to modular, service-driven design

✅ Backward Compatible — No breaking changes to controller or service APIs

⚙️ Technical Highlights
Dependency Injection: All providers registered and injected via @module setup

Error Handling: Used standard ConflictException, NotFoundException patterns

Logging: Retained logging in key providers (e.g., creation, deletion)

Validation: Moved and maintained all business rules (e.g., uniqueness checks) inside relevant services

Persistence: Each provider interacts with its own repository method

🧪 Status
✅ All functionality validated
✅ Unit tests updated and passing
✅ No regressions
✅ Readable, scalable, and production-ready

[phertyameen]

LGTM