jshint

What is jshint?

JSHint is a static code analysis tool used in software development for checking if JavaScript source code complies with coding rules. It helps developers identify potential errors and enforce coding standards.

What are jshint's main functionalities?

Basic Linting

This feature allows you to perform basic linting on a piece of JavaScript code. The code sample demonstrates how to use JSHint to check a simple JavaScript snippet for errors.

const jshint = require('jshint').JSHINT;
const code = 'var a = 1;';
const options = { esversion: 6 };
jshint(code, options);
console.log(jshint.errors);

Custom Configuration

JSHint allows you to customize the linting process with various options. This example shows how to enable the 'undef' option to check for the use of undefined variables.

const jshint = require('jshint').JSHINT;
const code = 'var a = 1;';
const options = { esversion: 6, undef: true };
jshint(code, options);
console.log(jshint.errors);

Using JSHint with Configuration File

You can use a configuration file (e.g., .jshintrc) to define your linting rules. This example demonstrates how to read a JavaScript file and a JSHint configuration file, then lint the code using the specified rules.

const fs = require('fs');
const jshint = require('jshint').JSHINT;
const code = fs.readFileSync('path/to/your/file.js', 'utf8');
const config = JSON.parse(fs.readFileSync('.jshintrc', 'utf8'));
jshint(code, config);
console.log(jshint.errors);

Other packages similar to jshint

eslint

ESLint is another popular JavaScript linting tool that is highly configurable and supports custom rules. It provides more flexibility and a larger ecosystem of plugins compared to JSHint.

jscs

JSCS (JavaScript Code Style) is a code style linter for JavaScript. It focuses more on enforcing coding style conventions rather than finding potential errors. It has been merged with ESLint, but older versions are still in use.

tslint

TSLint is a linter for TypeScript, which is a superset of JavaScript. It provides similar functionality to JSHint but is specifically designed for TypeScript code. TSLint is now deprecated in favor of ESLint with TypeScript support.

README

JSHint, A Static Code Analysis Tool for JavaScript

JSHint is a community-driven tool to detect errors and potential problems in JavaScript code and to enforce your team's coding conventions. We made JSHint very flexible so you can easily adjust it to your particular coding guidelines and the environment you expect your code to execute in.

Our goal is to help JavaScript developers write complex programs without worrying about typos and language gotchas.

We believe that static code analysis programs—as well as other code quality tools—are important and beneficial to the JavaScript community and, thus, should not alienate their users.

For general usage and hacking information, visit our website: http://jshint.com/.

Bug Bounties

Some bugs are so important to us, we will pay you if you fix them! Go to our page on BountySource to see which bugs have bounties behind them.

Really want to have something fixed but don't have time? You can add your own bounty to any JSHint bug and make it more attractive for potential contributors!

Rule: A bug is considered fixed only after it has been merged into the master branch of the main JSHint repository.

Reporting a bug

To report a bug simply create a new GitHub Issue and describe your problem or suggestion. We welcome all kind of feedback regarding JSHint including but not limited to:

• When JSHint doesn't work as expected
• When JSHint complains about valid JavaScript code that works in all browsers
• When you simply want a new option or feature

Before reporting a bug look around to see if there are any open or closed tickets that cover your issue. And remember the wisdom: pull request > bug report > tweet.

FAQ

How do I turn off "mixed tabs and spaces" warning?

If you're using so-called smart tabs then we have an option smarttabs for you. Otherwise, your solution is to run JSHint with a custom reporter that discards any warnings you don't like. For example, this example reporter discards all warnings about mixed tabs and spaces.

Contributing

Look for a file named CONTRIBUTING.md in this repository. It contains our contributing guidelines. We also have a mailing list.

License

JSHint is distributed under the MIT License. One file and one file only (src/stable/jshint.js) is distributed under the slightly modified MIT License.

Attribution

Core Team members:

• Anton Kovalyov (@valueof)
• Wolfgang Kluge (blog)
• Josh Perez (@goatslacker)
• Brent Lintner (@brentlintner)

Maintainer: Anton Kovalyov

Thank you!

We really appreciate all kind of feedback and contributions. Thanks for using and supporting JSHint!

Changelog

2.0.0 (2013-05-08)

WARNING: This release introduces backwards incompatible changes.

JSHint 2.0.0 is out! This version hits a pretty big milestone for the project: this is the first JSHint release for which I'm not the biggest contributor. I personally believe this fact validates JSHint as a successful open source project. And I'm extremely thankful to all you who file bug reports and send patches—you're all awesome.

EcmaScript 5

The first and foremost: starting with this version JSHint will assume ES5 as the default environment. Before, JSHint was checking all the code per ES3 specification with an option to enable ES5 mode. Now ES5 mode is the default mode and if you want to check your code against the ES3 specification (useful when developing for super old browsers such as Internet Explorer 6) you will have to use es3:true.

Special thanks to Rick Waldron for championing this change.

Partial support for Mozilla JavaScript extensions and ES6

Thanks to our newest core contributor, Bernard Pratz, JSHint now has partial support for Mozilla JavaScript extensions (moz option) and ES6 (esnext option):

• Destructuring assignment
• const
• let blocks and expressions
• Generators and iterators
• List comprehension
• Try/catch filters and multiple catch blocks
• Concise method declaration
• for ... of loops
• Fat arrows

We have more patches in queue that add support for classes and other nifty ES6 things. Stay tuned!

CLI

• JSHint now looks for .jshintrc in the directory being linted. (#833)
• Various cross-platform fixes for our Node CLI module.
• New public method for the CLI export that allows third-parties to hook into the file resolution logic. (#741)

General

• For non-Node system we upgraded to the latest version of Browserify. This resolves some performance issues we had with Rhino.

• Added SVG globals to the browser environment.

• Option smarttabs now ignores mixed tabs and spaces within single- and multi-line comments.

• Added a new pragma to unignore a warning:

  /*jshint -W096 */
  
  // All warnings about keys producing unexpected results will
  // be ignored here.
  
  /*jshint +W096 */
  
  // But not here.
  

• JSHint now ignores unrecognized JSLint options.

• Fixed a bug where indent:false was triggering indentation warnings. (#1035)

• Fixed a regression bug where unused was not behaving correctly. (#996)

• Plus lots and lots of other, smaller bug fixes.

New rapid release schedule

And last but not least: starting with this version, I'm switching JSHint to a more rapid release schedule. This simply means that I will be publishing new versions of JSHint more often. I will try my best to follow semver recommendations and ship working software. But as our license says, no guarantees.

Thanks to Bernarnd Pratz, Michelle Steigerwalt, Yuya Tanaka, Matthew Flaschen, Juan Pablo Buritica, Matt Cheely, Steve Mosley, Stephen Sorensen, Rick Waldron, Hugues Malphettes, Jeff Thompson, xzyfer, Lee Leathers, croensch, Steven Benner, James Allardice, Sindre Sorhus, Jordan Harband, Stuart Knightley and Kevin Locke for sending patches!

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