Development Guide

Development Guide

Guidelines for developing and contributing to the DevCom Social Media API.

Development Setup

Prerequisites

• Node.js 20.x
• MongoDB 7.0
• Git
• VS Code (recommended) or your preferred IDE

Initial Setup

# Clone repository
git clone https://github.com/your-username/DevCom_Node.git
cd DevCom_Node

# Install dependencies
npm install

# Copy environment file
cp .env.example .env

# Start MongoDB (using Docker)
docker-compose up -d mongodb

# Start development server
npm run dev

Code Structure

Adding a New Feature

1. Create Module Structure

src/modules/new-feature/
├── new-feature.controller.ts
├── new-feature.service.ts
├── new-feature.repository.ts
├── new-feature.dto.ts
└── new-feature.routes.ts

2. Create Model (if needed)

src/database/models/NewFeature.model.ts

3. Add Routes

Update src/routes/index.ts:

import newFeatureRoutes from "../modules/new-feature/new-feature.routes";

router.use("/new-feature", newFeatureRoutes);

Coding Standards

TypeScript

• Use TypeScript for all new code
• Avoid any types - use proper types or unknown
• Use interfaces for object shapes
• Prefer const over let

Naming Conventions

• Files: kebab-case.ts (e.g., user-profile.controller.ts)
• Classes: PascalCase (e.g., UserController)
• Functions/Methods: camelCase (e.g., getUserProfile)
• Constants: UPPER_SNAKE_CASE (e.g., MAX_RETRY_COUNT)
• Interfaces: I prefix (e.g., IUser)

Code Organization

// 1. Imports (external first, then internal)
import express from "express";
import { AppError } from "../../common/exceptions/AppError";

// 2. Interfaces/Types
interface MyInterface {
  // ...
}

// 3. Constants
const CONSTANT = "value";

// 4. Class/Function
export class MyClass {
  // ...
}

Error Handling

Always use asyncHandler for async route handlers:

import { asyncHandler } from "../../common/utils/asyncHandler";

export class MyController {
  myMethod = asyncHandler(async (req: Request, res: Response) => {
    // Your code here
  });
}

Validation

Use Zod schemas for validation:

import { z } from "zod";

export const createSchema = z.object({
  name: z.string().min(1, "Name is required"),
  email: z.string().email("Invalid email"),
});

export type CreateDTO = z.infer<typeof createSchema>;

Testing

Running Tests

npm test

Writing Tests

• Unit tests for services
• Integration tests for API endpoints
• Test coverage should be > 80%

Git Workflow

Branch Naming

• feature/feature-name - New features
• bugfix/bug-name - Bug fixes
• hotfix/issue-name - Critical fixes
• refactor/refactor-name - Code refactoring

Commit Messages

Follow conventional commits:

feat: add user profile update endpoint
fix: resolve authentication token expiration issue
docs: update API documentation
refactor: improve error handling in services
test: add unit tests for user service

Pull Request Process

1. Create a feature branch
2. Make your changes
3. Write/update tests
4. Update documentation
5. Create pull request
6. Address review comments
7. Merge after approval

Code Review Checklist

• Code follows style guidelines
• All tests pass
• No TypeScript errors
• Documentation updated
• Error handling implemented
• Security considerations addressed
• Performance optimized (if applicable)

Debugging

Enable Debug Logging

Set in .env:

NODE_ENV=development

View Logs

Logs are written to:

• logs/error.log - Error logs
• logs/combined.log - All logs
• Console output (development mode)

Common Issues

MongoDB Connection:

# Check MongoDB status
mongosh --eval "db.adminCommand('ping')"

Port Already in Use:

# Find process using port 3000
lsof -i :3000
# Kill process
kill -9 <PID>

Performance Tips

1. Database Indexes - Add indexes for frequently queried fields
2. Pagination - Always paginate large datasets
3. Caching - Consider Redis for frequently accessed data
4. Query Optimization - Use select() to limit fields
5. Connection Pooling - MongoDB handles this automatically

Security Best Practices

1. Never commit secrets - Use .env file
2. Validate all inputs - Use Zod schemas
3. Sanitize user input - Prevent injection attacks
4. Use HTTPS - In production
5. Rate limiting - Already implemented
6. Password hashing - bcrypt with salt rounds

Documentation

Code Comments

• Use JSDoc for public methods
• Explain "why" not "what"
• Keep comments up to date

API Documentation

• Update wiki when adding endpoints
• Include request/response examples
• Document error cases

Resources

• TypeScript Handbook
• Express.js Guide
• Mongoose Docs
• Zod Documentation

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Questions? Open an issue or contact the maintainers.