🚀 React Best Practices for Scalable Frontends: Part 1 – Folder Structure and Organization

Introduction

Building a scalable frontend system isn’t a one-time task; it’s an ongoing journey of refining your code, improving your architecture, and preparing your application for future growth. Whether you’re starting with a simple monolithic app or planning for a distributed system, your code structure and organization will play a significant role in your success.

React, while incredibly flexible, doesn’t enforce strict architectural patterns. This freedom is powerful but can quickly become overwhelming without clear guidelines. In this first part of our series on React Best Practices, we’ll dive deep into one of the most critical foundations for scalability: Consistent Folder Structure and Code Organization.

By the end of this article, you’ll have a clear understanding of how to structure your React project, optimize exports, organize your tests, enforce code quality, and maintain documentation.

Let’s get started.

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📂 1. Consistent Folder Structure and Code Organization

A consistent and logical folder structure is the backbone of a scalable React application. It enhances readability, maintainability, and scalability—essential factors for projects of any size.

🛠️ 1.1 Choosing the Right Project Structure

The way you organize your project files directly impacts how quickly developers can understand, navigate, and contribute to the codebase.

Feature-Based Structure

In a Feature-Based Structure, files are grouped by features or UI components. This approach is best suited for small to medium-sized projects.

Example Folder Structure:

/src
  /components
    /Auth
      Login.jsx
      Signup.jsx
    /Dashboard
      Dashboard.jsx
      Analytics.jsx
  /hooks
    useAuth.js
  /utils
    helpers.js

When to Use It:

• Projects with a moderate number of features.
• Teams working on isolated features independently.

Pros:

• Easy to locate and understand feature-related files.
• Promotes modularity and separation of concerns.

Cons:

• As the project scales, the structure can become cluttered.

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Domain-Based Structure

In a Domain-Based Structure, files are grouped by business domains rather than individual features. This is more suitable for large-scale applications.

Example Folder Structure:

/src
  /auth
    Login.jsx
    Signup.jsx
    hooks.js
    helpers.js
  /dashboard
    Dashboard.jsx
    Analytics.jsx
    hooks.js
    helpers.js
  /shared
    /components
    /hooks
    /utils

When to Use It:

• Applications with multiple domains or bounded contexts.
• Large teams with domain-specific responsibilities.

Pros:

• Scales well as the project grows.
• Encourages encapsulation of domain-specific logic.

Cons:

• Requires more discipline to prevent duplication.

💡 Recommendation: Start with a **Feature-Based* Structure if you're unsure. Transition to a Domain-Based Structure as your project grows in complexity.

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📦 1.2 Export Conventions: Default vs Named Exports

Consistency in exports avoids confusion, reduces cognitive load, and simplifies imports across your project.

Default Exports for Components

Use default exports for React components.

Why?

• Simplifies imports.
• Allows for easy renaming during imports.

Example:

// Button.jsx
const Button = () => <button>Click Me</button>;
export default Button;

Importing:

import Button from './Button';

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Named Exports for Utilities and Hooks

For utilities, constants, and custom hooks, use named exports.

Why?

• Clear visibility of available exports.
• Prevents accidental overwrites during imports.

Example:

// hooks.js
export const useAuth = () => { /* ... */ };
export const useTheme = () => { /* ... */ };

Importing:

import { useAuth, useTheme } from './hooks';

💡 Best Practice: Stick to default exports for components and named exports for utilities and hooks to maintain clarity.

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🧪 1.3 Organizing Tests: Colocated vs Separate Test Files

A strong testing strategy depends not only on what you test but also where you place your test files.

Colocated Tests

For smaller or medium-sized projects, colocating test files alongside components keeps related files close together.

Example:

/components
  Button.jsx
  Button.test.jsx

Pros:

• Easier to locate and maintain tests.
• Encourages testing during development.

Cons:

• Test files can overcrowd component folders, reducing clarity.
• Managing and navigating tests becomes harder in large projects.

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Separate Test Folder

In larger applications, keeping tests in a dedicated folder can provide better organization.

Example:

/src
  /tests
    /components
      Button.test.jsx

Pros:

• Better separation between source and test code.
• Easier to run and manage tests across the project.

Cons:

• It’s easy for test files to fall out of sync with their corresponding source files.
• Jumping between /src and /tests folders can slow down development.

💡 Recommendation: Start with colocated tests for smaller projects. For larger projects with dedicated QA resources, a separate /tests folder is often more effective.

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🛡️ 1.4 Enforcing Code Quality: Tools You Should Use

Maintaining high code quality is crucial for scalability. Here are the tools you should integrate:

• ESLint: Enforce coding standards and catch errors.
• Prettier: Automatically format your code for consistency.
• Checkspeller: Avoid embarrassing typos in code and documentation.

Best Practice: Set these tools as part of your CI/CD pipeline to ensure every commit meets your project’s quality standards.

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📑 1.5 Documentation Practices: README is Your Front Door

A good README.md file serves as a manual for your project.

Essential README Elements:

• Project Overview: A brief description.
• Folder Structure Explanation: How files are organized.
• Setup Instructions: Steps to run the project.
• Testing Guide: How to run tests.

💡 Best Practice: Keep your README updated and informative—it’s the first impression of your project.

🏁 Conclusion

Scalable React applications start with a solid foundation. In this article, we covered:

• Choosing the right project structure for your needs.
• Establishing clear export conventions.
• Organizing tests effectively.
• Enforcing code quality standards with essential tools.
• Crafting clear documentation with an informative README.

In the next article, we’ll explore State Management in React, diving into best practices for managing state in your React application.

Stay tuned!