How to Organize Large React Application and Make it Scalable ?

React is a declarative, efficient, and flexible JavaScript library for building user interfaces. It’s ‘V’ in MVC. ReactJS is an open-source, component-based front-end library responsible only for the view layer of the application. It is essential to organize a large react app so that it can be easily scalable. There are several approaches you can take to organizing a large React application and making it scale. 

Let’s understand a few approaches to organizing a large react application and making it scale:

1. Use a modular architecture:

Modular architecture in React entails breaking down the application into smaller, self-contained components for better organization and code reusability. Implementation methods include using React components or tools like Webpack to create and import independent modules.

Example: Below is the code example

Javascript

import React from 'react';

const MyComponent = () => {
    return <div>Hello World!</div>;
}

export default MyComponent;

2. Use code-splitting:

Code splitting involves dividing the application’s code into smaller chunks that can be loaded on demand as needed, rather than loading all of the code at once. This can help to reduce the initial load time of the application and improve its overall performance, particularly for applications with a large codebase. In a React application, code splitting can be implemented using the React.lazy and Suspense components.

Example: Below is the code example

Javascript

import React, { Suspense } from 'react';

const OtherComponent = React.lazy(
    () => import('./OtherComponent'));

const MyComponent = () => {
    return (
        <Suspense fallback={<div>Loading...</div>}>
            <OtherComponent />
        </Suspense>
    );
}

3. Use a state management library:

In a large React application, the managing state can become complex and difficult to maintain, To help with this, you can use a state management library like Redux or MobX. These libraries provide a central store for the application states and make it easier to manage and update the state in a consistent and predictable way.

Example: Below is the code example

Javascript

import { createStore } from 'redux';

const initialState = {
    count: 0,
};

const reducer = (state = initialState, action) => {
    switch (action.type) {
        case 'INCREMENT':
            return {
                count: state.count + 1,
            };
        case 'DECREMENT':
            return {
                count: state.count - 1,
            };
        default:
            return state;
    }
};

const store = createStore(reducer);
store.dispatch({ type: 'INCREMENT' });
console.log(store.getState()); // { count: 1 }

4. Use a linter:

A linter is a tool that checks your code for potential issues and can help to ensure that your code adheres to a set of coding standards. This can include things like checking for syntax errors, enforcing a consistent style, and identifying potential issues with code quality or performance. Using a linter can help to keep your codebase clean and maintainable as the application grows, and can also help to catch issues early on and prevent them from becoming problems later on.

Example: Below is the code example

Javascript

{
    "extends": ["airbnb", "prettier"],
      "rules": {
        "no-console": "off",
        "react/jsx-filename-extension": [1,
            { "extensions": [".js", ".jsx"] }]
      }
}

5. Use testing:

Proper testing is crucial for maintaining the quality and stability of a large React application. This can include writing unit tests for individual components to ensure that they are working correctly, as well as integration tests for larger functionalities to ensure that everything is working together as expected. Testing can help to catch issues early on and prevent regressions as the application evolves, and can also help to ensure that changes to the codebase do not break existing functionality.

Example: Below is the code example

Javascript

import React from 'react';
import { shallow } from 'enzyme';
import MyComponent from './MyComponent';

describe('MyComponent', () => {
    it('renders the correct text', () => {
        const wrapper = shallow(<MyComponent />);
        expect(wrapper.text()).toEqual('Hello World!');
    });
});