Hack

Good news everyone, JSHint is open source! Our source code is hosted on GitHub.

Build Status

How to contribute

The best way to make sure your issue is addressed is to submit a patch. We accept patches through all mediums: pull requests, email, issue comment, tweet with a link to a snippet, graffiti outside of Anton's apartment, etc.

However, before sending a patch, please make sure that the following applies:

  • Your commit message links to that issue.
  • Your commit message is very descriptive (example).
  • Your patch doesn't have useless merge commits.
  • Your coding style is similar to ours (see below).
  • Your patch is 100% tested. We don't accept any test regressions.
  • All tests and lint checks pass (npm test).
  • You understand that we're super grateful for your patch.

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.

Development Environment

JSHint has a number of dependencies specified in its package.json file. To install them just run the following command from within your repo directory:

$ npm install

After that you will be able to run the edge version of JSHint using bin/jshint or build the release bundles using bin/build.

Coding Style

This section describes our coding style guide. You might not agree with it and that's fine but if you're going to send us patches treat this guide as a law.

Our main rule is simple:

All code in any code-base should look like a single person typed it, no matter how many people contributed. —idiomatic.js

Whitespace:

  • We use hard tabs everywhere.
  • Smart tabs are okay.
  • Use one space after if, for, while, etc.
  • Use one space after function for anonymous functions but not for named functions:

    var a = function () {};
    function a() {}
  • Feel free to indent variable assignments or property definitions if it makes the code look better. But don't abuse that:

    // Good
    var next = token.peak();
    var prev = token.peak(-1);
    var cur  = token.current;
    
    var scope = {
      name:   "(global)",
      parent: parentScope,
      vars:   [],
      uses:   []
    };
    
    // Bad
    var cur         = token.current;
    var isSemicolon = cur.isPunctuator(";");
  • Wrap multi-line comments with new lines on both sides.

Variables:

  • Use one var per variable unless you don't assign any values to it (and it's short enough):

    var token = tokens.find(index);
    var scope = scopes.current;
    var next, prev, cur;
  • Don't be overly descriptive with your variable names but don't abuse one-letter variables either. Find a sweet spot somewhere in between.

Comments:

  • Use // for all comments.
  • Comment everything that is not obvious.
  • If you're adding a new check, write a comment describing why this check is important and what it checks for.

Misc:

  • Always use strict mode.
  • Always use strict comparisons: === and !==.
  • Use semicolons.
  • Don't use comma-first notation.
  • Try not to chain stuff unless it really helps (e.g. in tests).
  • Don't short-circuit expressions if you're not assigning the result:

    // Good
    token = token || tokens.find(0);
    
    // Bad
    token.isPunctuator(";") && report.addWarning("W001");
    
    // Good
    if (token.isPunctuator(";"))
      report.addWarning("W001");

Today we use JSHint's white:true to enforce some of these rules. Eventually we'll switch to JSHint Next style enforcing component. But it's not ready yet.

License

Most files are under this license:

Copyright 2013 Anton Kovalyov (http://jshint.com)

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

One file, however, is under a slightly modified version of the license. Unfortunately, due to historical reasons and Crockford's stubborness we can't change it. Here's this modified license:

JSHint, by JSHint Community.

This file (and this file only) is licensed under the same slightly modified
MIT license that JSLint is. It stops evil-doers everywhere:

Copyright (c) 2002 Douglas Crockford  (www.JSLint.com)

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom
the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

The Software shall be used for Good, not Evil.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.