Setting up ESLINT in your JavaScript Project with VS Code

Damola Adekoya
Mar 20 · 5 min read

ESLINT: have you ever heard of ESLINT? or have you been wondering how to get started with ESLINT but you have no idea how to get started with ESLINT, But in few minutes with this article you will start using ESLINT in your next project. Yeah in few minutes

ESLINT is pluggable linting utility for Javascript and JSX, it help to discover possible errors.

VS Code is one of the top editor for development it was developed and maintain by Microsoft it help to improve productivity and also comes with many features, one of the feature i am going to emphasize on is extension. Extension are external packages in VS Code that allows you to extend the functionalities of your editor

you can download VS Code from their official website VS Code Download

NB: I won’t be digging deep into VS Code..everything on VS Code in this post will only be related to ESLINT.

steps:

  • create a javascript project
  • install eslint as an extension in your VS Code Editor
  • Install eslint as a global package using npm
  • initialize eslint in your javascript project
  • modify your eslint configuration file in your project.

let create a simple javascript project using

npm init --yes

after the operation was successful it will create a package.json file that will manage all configuration for our project.

let try to install ESLINT extension on vs code editor

once we have installed eslint extension on our vs code editor then let install eslint as a global package via npm using the below code

npm install eslint -g

you need to initialize eslint in your project so you can leverage the power of eslint. From your root project enter the below code to initialize eslint

eslint --init

during the initialization eslint will ask you some questions, more like to setup your configuration file.

How would you like to use ESLint?

  • To check syntax only => it helps you correct your syntax and make sure it conform to standard.
  • To check syntax and find problems => to help you check for syntax correctness and also help to find any problems in your code base
  • To check syntax, find problems, and enforce code style_ => to help you check for syntax, find problem and enforce style, enforcing style means to conforms to a particular coding standard such as Airbnb, Google and other Standard coding style. But I always go for the last option the one with syntax, find problems and enforce code style

What type of modules does your project use?

  • Javascript module (import/export) => if your project has babel installed then you definitely need to choose this option. If you are working on a project such as React, Vue, Angular e.t.c they all use babel so you need choose this option.
  • CommonJS (require/exports) => this option is meant for commonJS that has nothing to do with babel, maybe your nodejs project and any other javascript project

Which framework does your project use?

  • React => if you are using react in/for your project then this option is for you
  • Vue => if you are using Vue in/for your project then this option is for you
  • None of these => if you are using neither React or Vue in your project choose this option

Where does your code run?

  • Browser => if your project runs on browser e.g React, Angular, Vue e.t.c then go for this option
  • Node => if your project is a node based then gladly choose this option

How would you like to define a style for your project?

  • Use a popular style guide => This allows you to choose from set of popular style such as Airbnb,Standard and Google style guide, it is advisable to choose this option in order for you to follow popular and most used style guide and i will be choosen this option in this post.
  • Answer questions about your style: This is for custom style guide
  • Inspect your JavaScript file(s).: custom style guide

What format do you want your config file to be in?

  • Javascript => whether you want your eslint config file to be in .jsfile
  • YAML => whether you want your eslint config file to be in .yamlfile
  • JSON => whether you want your eslint config file to be in .jsonfile you can choose any option in this section

after you have chosen your preferred configuration file type it will then prompt you to install all necessary dependencies. after all neccessary dependencies has been successfully installed it will now generate a config file with “.eslintrc”.”js/json/yaml”.

example of the the configuration file shown below

below is a little animated image that show how vs code works with eslint to notify you of errors in your javascript project

Setting up rules for ESLINT in your project

Defining rules for ESLINT in your project informed eslint the kind of rules you want to add or remove. you can modify/set your rules in the rules section in the configuration file

example of rules to set are

"rules" : {
no-console: 0;
no-empty: 0;
no-irregular-whitespace:0;
}

you can define as many rules as possible, you can read more on ESLINT rules on their official documentation ESLINT Rules Documentation

Lastly, I am going to show you how you can link your eslint to your javascript project compiler/transpiler

steps below

  • Goto your package.json file, in the script segment in your file add the following
script:{
"lint":"eslint"
}

NB: “lint” is just an ordinary word, you can use any word you are comfortable with

then in your root project you can run your linting script with

npm run lint

Conclusion

ESLINT will helps you to increase your productivity, write your code according to standard and flag errors when your code base is breaking style guide rules. With this post you should be able to integrate ESLINT in your JavaScript project.

Damola Adekoya

Written by

A Software Engineer, passionate about JavaScript | Flutter | .NET | PHP

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