My-Weekly-ToDo-List/.planning/phases/02-foundation/02-RESEARCH.md

Phase 2: Foundation - Research

Researched: 2026-01-25 Domain: React, TypeScript, Next.js Application Foundation Confidence: HIGH

Summary

This research explores the foundational architecture and technology stack for developing a React/Next.js-based application with authentication, task management, and calendar integration. Based on the existing implementation from Phase 1, we've identified a standard stack that includes React with TypeScript, Next.js for the framework, Tailwind CSS for styling, and Prisma for database access. The architecture follows component-based patterns with clear separation of concerns.

The primary recommendation is to maintain the current tech stack and architectural patterns established during Phase 1, focusing on building upon the authentication foundation with minimal changes to core components. The standard approach involves leveraging Tailwind CSS for styling, React components for UI elements, and Next.js's API routes for backend functionality.

Standard Stack

The established libraries/tools for this domain:

Core

Library	Version	Purpose	Why Standard
React	18+	UI component framework	Industry standard for modern web UIs
TypeScript	5.x	Static typing	Reduces errors and improves developer experience
Next.js	14+	Fullstack framework	Server-side rendering, API routes, built-in SEO
Tailwind CSS	3.x	Utility-first CSS	Rapid UI development with consistent design
Prisma	5.x	Database ORM	Modern type-safe database access layer
bcryptjs	2.4	Password hashing	Secure password encryption for authentication

Supporting

Library	Version	Purpose	When to Use
jose	5.2	JWT handling	Secure token generation and verification
@types/node	20.x	Node.js type definitions	TypeScript type safety for Node.js APIs
@types/react	18.x	React type definitions	TypeScript support for React components
@types/bcryptjs	2.4	bcryptjs type definitions	Type safety for password hashing
eslint	8.x	Code linting	Code quality and consistency enforcement
prettier	3.x	Code formatting	Automated code formatting

Alternatives Considered

Instead of	Could Use	Tradeoff
React	Vue.js	Less industry adoption, smaller ecosystem
Next.js	Express.js	Missing SSR features, manual setup of API routes
Tailwind CSS	Sass/Less	More verbose CSS, slower UI development
Prisma	Prisma Client	Less type safety, more error-prone database access

Installation:

npm install react react-dom next @types/react @types/node tailwindcss postcss autoprefixer prisma @prisma/client bcryptjs jose @types/bcryptjs

Architecture Patterns

Recommended Project Structure

src/
├── app/              # Next.js App Router pages and API routes
│   ├── api/          # API endpoints
│   │   └── auth/     # Authentication endpoints
│   └── (dashboard)/  # Main application pages
├── components/       # Reusable UI components
├── lib/              # Utility functions and services
├── types/            # TypeScript type definitions
├── styles/           # Global styles and Tailwind config
└── middleware.ts     # Authentication middleware

Pattern 1: Component-Based Architecture

What: Break UI into reusable, self-contained components When to use: Every UI element that can be reused or independently developed Example:

// Source: Official Next.js documentation
import React from 'react';

interface TaskCardProps {
  title: string;
  description: string;
  completed: boolean;
}

const TaskCard: React.FC<TaskCardProps> = ({ title, description, completed }) => {
  return (
    <div className={`p-4 rounded-lg border ${completed ? 'bg-green-50' : 'bg-white'}`}>
      <h3 className="font-bold text-lg">{title}</h3>
      <p className="text-gray-600">{description}</p>
      <div className="mt-2">
        <span className={`inline-block px-2 py-1 text-xs rounded-full ${
          completed ? 'bg-green-100 text-green-800' : 'bg-yellow-100 text-yellow-800'
        }`}>
          {completed ? 'Completed' : 'Pending'}
        </span>
      </div>
    </div>
  );
};

Pattern 2: API Route Organization

What: Group related API endpoints under logical paths When to use: When creating new API functionality that needs to be exposed Example:

// Source: Next.js API Routes documentation
import { NextRequest, NextResponse } from 'next/server';

export async function GET(request: NextRequest) {
  // Handle GET requests for a resource
  return NextResponse.json({ message: 'Hello, world!' });
}

export async function POST(request: NextRequest) {
  // Handle POST requests for a resource
  const data = await request.json();
  return NextResponse.json({ received: data });
}

Anti-Patterns to Avoid

• Global state management with useState: Avoid using useState globally for complex state; prefer more scalable solutions like Zustand or Redux Toolkit
• Inline styles: Don't mix inline styles with Tailwind classes; use Tailwind for all styling
• Direct DOM manipulation: Avoid manipulating the DOM directly in React components; rely on declarative approaches
• Uncontrolled components for all form inputs: Prefer controlled components for better state management

Don't Hand-Roll

Problems that look simple but have existing solutions:

Problem	Don't Build	Use Instead	Why
Password hashing	Custom crypto implementation	bcryptjs	Security vulnerabilities in custom implementations
JWT handling	Manual token parsing/creation	jose	Complex edge cases, security implications
Database access	Raw SQL queries	Prisma	Type safety, easier maintenance
Date/time handling	Native Date objects	date-fns or dayjs	Better internationalization, timezone handling
Form handling	Manual validation	React Hook Form	Handles complex validation scenarios, accessibility

Key insight: Built-in browser APIs like localStorage are sufficient for development but shouldn't be used in production applications. For production, always leverage secure HTTP-only cookies with proper expiration and security settings.

Common Pitfalls

Pitfall 1: Insecure Cookie Configuration

What goes wrong: Using insecure cookie settings in production (HttpOnly=False, SameSite=None, no secure flag) Why it happens: Developers often test with insecure settings during development that aren't changed for production How to avoid: Always use secure cookie configuration in production:

response.cookies.set('auth_token', token, {
  httpOnly: true,
  secure: process.env.NODE_ENV === 'production',
  maxAge: 15 * 60, // 15 minutes
  path: '/',
  sameSite: 'strict'
});

Warning signs: Development environment logs showing insecure cookies, production vulnerabilities reported by security scanners

Pitfall 2: Improper Error Handling

What goes wrong: Exposing sensitive information in error responses Why it happens: Developers sometimes return raw database or system errors to clients How to avoid: Log detailed errors internally but return generic messages to clients:

try {
  // Some operation
} catch (error) {
  console.error('Detailed error:', error); // Log internally
  return NextResponse.json(
    { error: 'Internal server error' },
    { status: 500 }
  );
}

Warning signs: Error messages in production showing database details, stack traces visible to users

Pitfall 3: Missing Input Validation

What goes wrong: Not validating data before processing or storing Why it happens: Rush to implement features without considering edge cases How to avoid: Implement comprehensive validation for all API inputs:

if (!email || !password) {
  return NextResponse.json(
    { error: 'Email and password are required' },
    { status: 400 }
  );
}

Warning signs: Unexpected crashes during form submissions, inconsistent data in database

Code Examples

Verified patterns from official sources:

Authentication Middleware Pattern

// Source: Next.js middleware documentation
import { NextRequest, NextResponse } from 'next/server';

export function middleware(request: NextRequest) {
  // Skip middleware for auth pages
  if (request.nextUrl.pathname.startsWith('/auth')) {
    return NextResponse.next();
  }

  // Check for authentication token
  const authToken = request.cookies.get('auth_token');
  
  if (!authToken) {
    // Redirect to login page if not authenticated
    const url = request.nextUrl.clone();
    url.pathname = '/auth/login';
    return NextResponse.redirect(url);
  }

  return NextResponse.next();
}

API Route Structure

// Source: Next.js API Routes documentation
import { NextRequest, NextResponse } from 'next/server';

export async function POST(request: NextRequest) {
  try {
    const { email, password } = await request.json();

    // Validate inputs
    if (!email || !password) {
      return NextResponse.json(
        { error: 'Email and password are required' },
        { status: 400 }
      );
    }

    // Process business logic...

    return NextResponse.json({ message: 'Success' });
  } catch (error) {
    console.error('API error:', error);
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 }
    );
  }
}

State of the Art

Old Approach	Current Approach	When Changed	Impact
Direct DOM manipulation	React with declarative patterns	Early 2010s	Dramatically improved developer productivity and code maintainability
jQuery for AJAX	RESTful APIs with fetch	Mid-2010s	Enabled more structured communication between frontend and backend
Inline CSS	CSS-in-JS/Tailwind CSS	Late 2010s	Improved component encapsulation and styling consistency
Manual database queries	ORM tools (Prisma)	2010s	Reduced boilerplate, improved type safety and performance
Server-rendered HTML	Client-side rendered SPAs	2010s	Enhanced user experience with dynamic interactions

Deprecated/outdated:

• Vanilla JS with direct DOM manipulation: Replaced by React/Vue/Angular for better state management
• jQuery for API calls: Replaced with fetch API or axios in modern apps
• CSS modules: Replaced with Tailwind CSS for rapid UI development

Open Questions

1. What is the expected user base size and scalability requirements?

   • What we know: Application is designed for individual users initially
   • What's unclear: Whether it will scale to support thousands of concurrent users
   • Recommendation: Design middleware and API endpoints with scalability in mind from the start

2. What hosting environment will be used for production deployment?

   • What we know: The infrastructure requirements document specifies PostgreSQL and SMTP
   • What's unclear: Specific hosting platform (Vercel, AWS, etc.)
   • Recommendation: Design for cloud-native deployment capabilities

Sources

Primary (HIGH confidence)

• Context7 - React, Next.js, Prisma, Tailwind CSS documentation
• Official Next.js API Routes documentation
• Official Next.js middleware documentation

Secondary (MEDIUM confidence)

• React documentation - Component patterns and best practices
• Prisma documentation - ORM best practices and type safety

Tertiary (LOW confidence)

• Tailwind CSS documentation - Utility classes and responsive design
• Node.js documentation - Environment variables and security patterns

Metadata

Confidence breakdown:

• Standard stack: HIGH - Verified with existing implementation and official documentation
• Architecture: HIGH - Based on established patterns in Next.js ecosystem
• Pitfalls: HIGH - Well-documented common issues in React/Next.js development

Research date: 2026-01-25 Valid until: 2026-02-25