Implementation & Coding - AI-Powered Development

Create a [LANGUAGE] [COMPONENT_TYPE] for: [FUNCTIONALITY_DESCRIPTION]

Requirements:
- [REQUIREMENT_1]
- [REQUIREMENT_2]
- [REQUIREMENT_3]

Include:
1. Complete implementation with proper error handling
2. Comprehensive documentation/comments
3. Unit tests
4. Type definitions (if applicable)
5. Example usage
6. Performance considerations

Follow [FRAMEWORK/LIBRARY] best practices and modern coding standards.

Implement this function in [LANGUAGE]:

Function signature: [FUNCTION_SIGNATURE]
Purpose: [WHAT_IT_DOES]
Input: [INPUT_PARAMETERS]
Output: [EXPECTED_OUTPUT]
Edge cases: [EDGE_CASES_TO_HANDLE]

Requirements:
- Optimal time/space complexity
- Comprehensive error handling
- Clear documentation
- Unit tests included
- Follow [CODING_STANDARD]

Provide multiple implementation approaches if applicable.

Create a [FRAMEWORK] component for: [COMPONENT_PURPOSE]

Design requirements:
- [VISUAL_REQUIREMENTS]
- [INTERACTION_REQUIREMENTS]
- [ACCESSIBILITY_REQUIREMENTS]

Technical requirements:
- Props/state management
- Event handling
- Responsive design
- Performance optimization
- Error boundaries (if applicable)

Include:
1. Component implementation
2. Styling (CSS/styled-components)
3. TypeScript interfaces
4. Storybook stories
5. Unit tests

Create a Node.js Express endpoint for user authentication with JWT tokens.

Requirements:
- POST /api/auth/login
- Email/password validation
- JWT token generation
- Password hashing verification
- Rate limiting
- Error handling
- Input sanitization

const express = require('express');
const bcrypt = require('bcrypt');
const jwt = require('jsonwebtoken');
const rateLimit = require('express-rate-limit');
const { body, validationResult } = require('express-validator');
const User = require('../models/User');

const router = express.Router();

// Rate limiting
const loginLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 5, // limit each IP to 5 requests per windowMs
  message: 'Too many login attempts, please try again later.',
  standardHeaders: true,
  legacyHeaders: false,
});

// Validation middleware
const validateLogin = [
  body('email')
    .isEmail()
    .normalizeEmail()
    .withMessage('Please provide a valid email'),
  body('password')
    .isLength({ min: 6 })
    .withMessage('Password must be at least 6 characters long'),
];

// Login endpoint
router.post('/login', loginLimiter, validateLogin, async (req, res) => {
  try {
    // Check validation errors
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        message: 'Validation failed',
        errors: errors.array()
      });
    }

    const { email, password } = req.body;

    // Find user by email
    const user = await User.findOne({ email });
    if (!user) {
      return res.status(401).json({
        success: false,
        message: 'Invalid credentials'
      });
    }

    // Verify password
    const isPasswordValid = await bcrypt.compare(password, user.password);
    if (!isPasswordValid) {
      return res.status(401).json({
        success: false,
        message: 'Invalid credentials'
      });
    }

    // Generate JWT token
    const token = jwt.sign(
      {
        userId: user._id,
        email: user.email
      },
      process.env.JWT_SECRET,
      { expiresIn: '24h' }
    );

    // Return success response
    res.status(200).json({
      success: true,
      message: 'Login successful',
      token,
      user: {
        id: user._id,
        email: user.email,
        name: user.name
      }
    });

  } catch (error) {
    console.error('Login error:', error);
    res.status(500).json({
      success: false,
      message: 'Internal server error'
    });
  }
});

module.exports = router;

import React, { useState, useEffect, useCallback } from 'react';
import { debounce } from 'lodash';

interface SearchProps {
  onSearch: (query: string) => void;
  placeholder?: string;
  debounceMs?: number;
  className?: string;
}

interface SearchState {
  query: string;
  isLoading: boolean;
  error: string | null;
}

const SearchComponent: React.FC<SearchProps> = ({
  onSearch,
  placeholder = "Search...",
  debounceMs = 300,
  className = ""
}) => {
  const [state, setState] = useState<SearchState>({
    query: '',
    isLoading: false,
    error: null
  });

  // Debounced search function
  const debouncedSearch = useCallback(
    debounce((searchQuery: string) => {
      if (searchQuery.trim()) {
        setState(prev => ({ ...prev, isLoading: true, error: null }));
        try {
          onSearch(searchQuery.trim());
        } catch (error) {
          setState(prev => ({
            ...prev,
            error: 'Search failed. Please try again.'
          }));
        } finally {
          setState(prev => ({ ...prev, isLoading: false }));
        }
      }
    }, debounceMs),
    [onSearch, debounceMs]
  );

  // Handle input change
  const handleInputChange = (event: React.ChangeEvent<HTMLInputElement>) => {
    const newQuery = event.target.value;
    setState(prev => ({ ...prev, query: newQuery }));
    debouncedSearch(newQuery);
  };

  // Clear search
  const handleClear = () => {
    setState({ query: '', isLoading: false, error: null });
    onSearch('');
  };

  return (
    <div className={`search-component ${className}`}>
      <div className="search-input-container">
        <input
          type="text"
          value={state.query}
          onChange={handleInputChange}
          placeholder={placeholder}
          className="search-input"
          aria-label="Search input"
        />
        {state.query && (
          <button
            onClick={handleClear}
            className="clear-button"
            aria-label="Clear search"
          >
            ✕
          </button>
        )}
        {state.isLoading && (
          <div className="loading-indicator" aria-label="Loading">
            ⟳
          </div>
        )}
      </div>
      {state.error && (
        <div className="error-message" role="alert">
          {state.error}
        </div>
      )}
    </div>
  );
};

export default SearchComponent;

Generate comprehensive tests for this [LANGUAGE] code:

[CODE_TO_TEST]

Create tests covering:
1. Happy path scenarios
2. Edge cases and error conditions
3. Input validation
4. Performance considerations
5. Integration scenarios (if applicable)

Use [TESTING_FRAMEWORK] and include:
- Setup and teardown
- Mocking strategies
- Assertion patterns
- Test data factories
- Coverage considerations

Refactor this code to improve:
[CODE_TO_REFACTOR]

Focus on:
1. Code readability and maintainability
2. Performance optimization
3. Design pattern implementation
4. Error handling improvement
5. Type safety (if applicable)
6. Documentation enhancement

Explain each change and its benefits. Maintain existing functionality while improving code quality.

Debug this issue in [LANGUAGE]:

Code: [PROBLEMATIC_CODE]
Error/Issue: [ERROR_DESCRIPTION]
Expected behavior: [EXPECTED_OUTCOME]
Current behavior: [ACTUAL_OUTCOME]

Provide:
1. Root cause analysis
2. Step-by-step debugging approach
3. Fixed code with explanations
4. Prevention strategies
5. Testing recommendations

Review this code for quality and best practices:

[CODE_TO_REVIEW]

Evaluate:
1. Code structure and organization
2. Naming conventions
3. Error handling
4. Performance implications
5. Security considerations
6. Maintainability
7. Documentation quality
8. Test coverage

Provide specific improvement suggestions with examples.

// Define interfaces first
interface UserService {
  createUser(userData: CreateUserRequest): Promise<User>;
  getUserById(id: string): Promise<User | null>;
  updateUser(id: string, updates: UpdateUserRequest): Promise<User>;
  deleteUser(id: string): Promise<void>;
}

// Then implement
class UserServiceImpl implements UserService {
  // Implementation follows interface contract
}

Generate a CRUD service class for [ENTITY_NAME] with:
- TypeScript interfaces
- Error handling
- Validation
- Database operations
- Logging
- Unit tests

class ApiError extends Error {
  constructor(
    public statusCode: number,
    message: string,
    public code?: string
  ) {
    super(message);
    this.name = 'ApiError';
  }
}

const handleApiError = (error: unknown): ApiError => {
  if (error instanceof ApiError) return error;

  return new ApiError(
    500,
    'Internal server error',
    'INTERNAL_ERROR'
  );
};

Step 1: Generate data models for [FEATURE]
Step 2: Create service layer with business logic
Step 3: Implement API endpoints
Step 4: Build frontend components
Step 5: Add comprehensive tests
Step 6: Generate documentation

interface Repository<T> {
  findById(id: string): Promise<T | null>;
  findAll(filters?: any): Promise<T[]>;
  create(entity: Omit<T, 'id'>): Promise<T>;
  update(id: string, updates: Partial<T>): Promise<T>;
  delete(id: string): Promise<void>;
}

class UserRepository implements Repository<User> {
  // Implementation with database operations
}

interface ServiceFactory {
  createUserService(): UserService;
  createOrderService(): OrderService;
  createPaymentService(): PaymentService;
}

class ServiceFactoryImpl implements ServiceFactory {
  // Factory implementation
}