ESLint is a

static code analysis In computer science, static program analysis (or static analysis) is the analysis of computer programs performed without executing them, in contrast with dynamic program analysis, which is performed on programs during their execution. The term ...

tool for identifying problematic patterns found in

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of Website, websites use JavaScript on the Client (computing), client side ...

code. It was created by Nicholas C. Zakas in 2013. Rules in ESLint are configurable, and customized rules can be defined and loaded. ESLint covers both code quality and coding style issues. ESLint supports current standards of

ECMAScript ECMAScript (; ES) is a JavaScript standard intended to ensure the interoperability of web pages across different browsers. It is standardized by Ecma International in the documenECMA-262 ECMAScript is commonly used for client-side scripting o ...

, and experimental syntax from drafts for future standards. Code using JSX or

TypeScript TypeScript is a free and open source programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are ...

can also be processed when a plugin or transpiler is used.

History

Both

JSLint JSLint is a static code analysis tool used in software development for checking if JavaScript source code complies with coding rules. It is provided primarily as a browser-based web application accessible through the domain jslint.com, but there ...

and

JSHint JSHint is a static code analysis tool used in software development for checking if JavaScript source code complies with coding rules. JSHint was created in 2011 by Anton Kovalyov as a fork of the JSLint project (by Douglas Crockford). Anton and o ...

were lacking the ability to create additional rules for code quality and coding style. After contributing to JSHint, Zakas decided to create a new

linting Lint, or a linter, is a static code analysis tool used to flag programming errors, bugs, stylistic errors and suspicious constructs. The term originates from a Unix utility that examined C language source code. History Stephen C. Johnson, a co ...

tool in June 2013, ESLint (originally called JSCheck, but renamed a month later), where all rules are configurable, and additional rules can be defined or loaded at run-time. In April 2016, the ESLint project joined the

jQuery Foundation The OpenJS Foundation is an organization that was founded in 2019 from a merger of JS Foundation and Node.js Foundation. OpenJS Promotes the JavaScript and web ecosystem by hosting projects and funds activities that benefit the ecosystem. The OpenJ ...

. Later that year, jQuery Foundation merged with Dojo Foundation to become

JS Foundation The OpenJS Foundation is an organization that was founded in 2019 from a merger of JS Foundation and Node.js Foundation. OpenJS Promotes the JavaScript and web ecosystem by hosting projects and funds activities that benefit the ecosystem. The OpenJ ...

as a Linux Foundation project. In October 2017, the ESLint project became a "Graduate Project" of the JS Foundation through its mentorship program. As of March 2019, ESLint is part of the

OpenJS Foundation The OpenJS Foundation is an organization that was founded in 2019 from a merger of JS Foundation and Node.js Foundation. OpenJS Promotes the JavaScript and web ecosystem by hosting projects and funds activities that benefit the ecosystem. The Open ...

, following a merge between the JS Foundation and Node.js Foundation.

Adoption

JetBrains JetBrains s.r.o. (formerly IntelliJ Software s.r.o.) is a Czech software development company which makes tools for software developers and project managers. , the company has offices in Prague; Munich; Berlin; Boston, Massachusetts; Ams ...

provides integrated support for ESLint in their WebStorm code editor, which runs the ESLint software as configured for the current text file, and displays any warnings near the offending lines of code in the editor. Since 2016, the

Vue.js Vue.js (commonly referred to as Vue; pronounced "view") is an open-source model–view–viewmodel front end JavaScript framework for building user interfaces and single-page applications. It was created by Evan You, and is maintained by him ...

project provides an ESLint plugin to automatically validate use of Vue.js templates and other features. Since 2018, this plugin is also promoted in the wizard for creating new Vue.js projects. In October 2018, the

React REACT or React may refer to: Science and technology *REACT (telescope), a telescope at Fenton Hill Observatory, New Mexico, US Computing * React (JavaScript library) , a JavaScript library for building user interfaces, from Facebook ** React Nati ...

project (developed by

Facebook Facebook is an online social media and social networking service owned by American company Meta Platforms. Founded in 2004 by Mark Zuckerberg with fellow Harvard College students and roommates Eduardo Saverin, Andrew McCollum, Dustin M ...

) published an official ESLint plugin to help enforce their coding rules. As of 2021, ESLint is the most commonly used JavaScript linter and is being downloaded over 14,000,000 times per week.

References

External links

* {{JavaScript JavaScript programming tools Static program analysis tools