backend answer module

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date: 2025-07-24 topics: [nodejs, backend, architecture, clean-code, devflow] day: 8

📘 Day 8 – DevFlow: Answer Module + Clean Backend Architecture

✅ What I Worked On

• Designed & implemented Answer module with a scalable backend structure
• Applied proper layered architecture: Controller → Service → Repository
• Added secure deletion logic: Only the author can delete their answer
• Integrated Husky + lint-staged for automated code formatting/linting

🧠 Key Highlights

🧱 Layered Backend Design

• Built Controller → Service → Repository abstraction
• Followed single responsibility principle (SRP)
• Connected Mongoose models via BaseRepository

🔐 Secure Answer Deletion Logic

if (answer.userId !== req.user.id) {
  throw new UnauthorizedError('Not allowed');
}

✅ Prevents users from deleting others' answers ✅ Enforces strict ownership in business logic layer

🧪 AnswerService Architecture

• Input validation via custom validator
• Added methods like createAnswer, findByUser, findAnswerById
• Unit-testable service with clear doc comments

🗃️ Repository Pattern

• Used BaseRepository to avoid duplicate DB logic
• Custom methods for queries (e.g., findByUser, getByQuestionId)
• Keeps data access abstracted and clean

📋 Swagger + JSDoc Style Route Docs

/**
 * @route   POST /api/v1/answers
 * @desc    Create new answer
 * @access  Private
 */

Helps devs onboard quickly and keeps APIs self-documented

🧼 Code Quality Automation with Husky

• pre-commit → npm run lint:fix
• pre-push → format checks or tests
• Ensures no messy code lands in the repo

❌ Blockers

• Small issue with TypeScript hinting on inherited repository methods (resolved)
• Swagger parsing didn't like multiline JSDoc comments at first

🧠 Reflection

I didn’t just write code — I built the foundation for something scalable. Security, structure, and automation are now baked into DevFlow.

“Speed is nothing without stability — and that’s what architecture gives.”

🔜 Next Up

• Finish AnswerController: update, getById, getAllByQuestionId
• Add unit tests for service logic
• Consider adding soft delete for future moderation features

🔗 References / Code

• 💻 DevFlow GitHub Repo
• 💻 commit