ESLint Plugin React

ESLint Plugin

ESLint Plugin is a powerful extension of the ESLint tool, the famous JavaScript linter. ESLint Plugins contain additional rules, customizations, and functionalities for ESLint. There are a variety of ESLint Plugins available, covering various aspects.
 

One widespread use case for ESLint Plugins is for specific frameworks or libraries like React, Vue.js, or TypeScript. These plugins provide rules to catch common errors and enforce best practices for those frameworks or languages. For example, the ESLint Plugin React, which we will discuss further, offers a set of rules dedicated to React development, ensuring that your code follows React's conventions and guidelines.

Now let's discuss ESLint Plugin React in detail.

ESLint Plugin React

As we discussed, ESLint Plugin React is a type of plugin that offers a set of rules specially dedicated to React applications, helping developers identify and fix errors and ensuring that the source code follows React's syntax. It helps in improving code's readability and maintainability.

To install ESLint, execute the following command:

# Using npm
npm install eslint --save-dev

Now, let us start by installing ESLint Plugin React. We can install it both globally and locally. However, it is recommended you must install it locally.

To show ESLint Plugin React, let's create a React project named "react-1stproject" using the following command:

npx create-react-app project_name

After completing the project creation, move to the project folder using the cd command. You can open the project in a code editor like VS code. You will see there is no file named ".eslintrc.json". Now, to generate this file, we will use the following command to initialize the eslint:

eslint –init

Note: If you get the error," 'eslint' is not recognized as an internal or external command, operable program or batch file." Then you should run "npm -g i eslint-cli" and "npm i eslint --save-dev" before executing the above command.
 

It will ask you some questions, which you need to answer. You can see the above image for reference. A new file named ".eslintrc.json" is created. We can now customize the file according to our needs,

Open the file "package. json". In "scripts," add the following line of code to run the lint command.

"lint": "eslint src/**/*.js"

The "src/**/*.js" represents the folder structure to which the eslint rules must be applied. After saving the file, let us run the command "npm run lint" on cmd.

You can see multiple types of errors, including indentation, etc. You can see there in the end that there are 40 errors, out of which ESLint can fix 31. To try to fix them, let us add one more command in "scripts."

"lint-fix": "eslint src/**/*.js --fix"

Save the package.json file and run the command "npm run lint-fix." It will automatically solve the errors that ESLint Plugin React can fix.

As you can see, only 9 errors are left out, 40 errors. Also, we are getting a warning.

Warning: React version not specified in eslint-plugin-react settings.

We can add the following code block in the ".eslintrc.json" file to deal with this warning.
 

"settings": {
	"react":{
		"version": "detect"
	}
},

It will automatically detect the react version, so there is no need to specify it from now. Also, to include React in scope using JSX, we add the following command in "rules":
 

"react/react-in-jsx-scope": "off"

We run the command "npm run lint-fix" again to check whether the warning and the error are fixed.

So, both were fixed. Now, we are only left with 2 errors. As both of these errors are in "App.test.js," so we add "jest": true in "env." It includes all the 'text', 'expect', etc.

All the errors are fixed, concluding that ESLint Plugin React is successfully running in our React project. 

Example

Let us discuss one example to show the working of ESLint Plugin React.

Code:

import logo from './logo.svg';
import './App.css';

function App() {
	return (
		<div className="App">
			<header class="App-header">
				<img src={logo} className="App-logo" alt="logo" />
				<p>
		  Edit <code>src/App.js</code> and save to reload.
				</p>
				<a
					className="App-link"
					href="https://reactjs.org"
					target="_blank"
					rel="noopener noreferrer"
				>
		  Learn React
				</a>
			</header>
		</div>
	);
}
export default App;

The above code is the basic "App.js" file generated when we create a react project. Now to see the working of ESLint Plugin React, we will create some syntax errors in code and let ESLint automatically fix them.

The below image shows that we have changed "className" to "class." As "class" is an unknown property, we will use ESLint to fix this error.

We will run the "npn rum lint" command to identify the error. Refer to the below image.

To fix this error, we will run the command we created earlier, "npn run list-fix."

As we can see, ESLint Plugin React fixed the error, and it also made changes to the "App.js" file.

Benefits of ESLint Plugin React

Let us see some of the benefits of using ESLint Plugin React.

• Identify Errors: ESLint Plugin React helps to identify potential errors in our source code. It can detect errors such as undefined variables, missing imports, etc. This saves us time and energy.
   
• Code Consistency: Consistently following a specific coding style is crucial, especially in team projects. ESLint Plugin React enforces coding conventions and standards, such as consistent indentation, naming conventions, etc. The plugin improves code readability.
   
• Ability to customize: ESLint Plugin React provides a high degree of customizability. We can enable or disable specific rules, configure additional plugins to extend their functionality, etc. This helps us modify the linting rules to our requirements and style.

Frequently Asked Questions

What is ESLint Plugin React?

ESLint Plugin React is a popular extension of the JavaScript linter, ESLint. It provides a set of rules only for React. It is used to identify errors and automatically fix them. The rules help programmers fix errors, saving time and energy and also improve code readability.

Can we use ESLint Plugin React on any IDE?

We can integrate ESLint Plugin React with all popular IDEs. Install the ESLint extension, and configure it according to your requirements to run it automatically on your files as you edit. This provides real-time feedback and suggestions, helping you adhere to the defined rules while coding.

Which languages can linters be used with?

Linters are available for various programming languages, including JavaScript, Python, Java, Ruby, and more. There are specific linters created for each language, providing language-specific rules and checks. Some popular linters include ESLint(JavaScript and JSX) and Pylint(Python).

Conclusion

We expect this article was insightful and that you learned something new today. In this blog, we learned about ESLint Plugin React. It is an extension of ESLint, a JavaScript linter that provides a set of rules, especially for React. It identifies and fixes the errors automatically, improving the code readability. We discuss how to add ESLint Plugin React to your React project and customize it. We also saw one example showing the working of ESLint saving our time and energy.
 

If you want to learn more about React, do visit.

• ReactJs
• Rules of Hooks
• The "package.json" guide
• React Native Testing
   

You may refer to our Guided Path on Code Studios for enhancing your skill set on DSA, Competitive Programming, System Design, etc. Check out essential interview questions, practice our available mock tests, look at the interview bundle for interview preparations, and so much more!

Happy Learning, Ninja!