jQuery — New Wave JavaScript
Contribution Guides
In the spirit of open source software development, jQuery always encourages community code contribution. To help you get started and before you jump into writing code, be sure to read these important contribution guidelines thoroughly:
Environments in which to use jQuery
- Browser support
- jQuery also supports Node, browser extensions, and other non-browser environments.
What you need to build your own jQuery
To build jQuery, you need to have the latest Node.js/npm and git 1.7 or later. Earlier versions might work, but are not supported.
For Windows, you have to download and install git and Node.js.
macOS users should install Homebrew. Once Homebrew is installed, run brew install git
to install git,
and brew install node
to install Node.js.
Linux/BSD users should use their appropriate package managers to install git and Node.js, or build from source
if you swing that way. Easy-peasy.
How to build your own jQuery
First, clone the jQuery git repo.
Then, enter the jquery directory and run the build script:
1 | cd jquery && npm run build |
The built version of jQuery will be put in the dist/
subdirectory, along with the minified copy and associated map file.
If you want to create custom build or help with jQuery development, it would be better to install grunt command line interface as a global package:
1 | npm install -g grunt-cli |
Make sure you have grunt
installed by testing:
1 | grunt -V |
Now by running the grunt
command, in the jquery directory, you can build a full version of jQuery, just like with an npm run build
command:
1 | grunt |
There are many other tasks available for jQuery Core:
1 | grunt -help |
Modules
Special builds can be created that exclude subsets of jQuery functionality.
This allows for smaller custom builds when the builder is certain that those parts of jQuery are not being used.
For example, an app that only used JSONP for $.ajax()
and did not need to calculate offsets or positions of elements could exclude the offset and ajax/xhr modules.
Any module may be excluded except for core
, and selector
. To exclude a module, pass its path relative to the src
folder (without the .js
extension).
Some example modules that can be excluded are:
- ajax: All AJAX functionality:
$.ajax()
,$.get()
,$.post()
,$.ajaxSetup()
,.load()
, transports, and ajax event shorthands such as.ajaxStart()
. - ajax/xhr: The XMLHTTPRequest AJAX transport only.
- ajax/script: The
<script>
AJAX transport only; used to retrieve scripts. - ajax/jsonp: The JSONP AJAX transport only; depends on the ajax/script transport.
- css: The
.css()
method. Also removes all modules depending on css (including effects, dimensions, and offset). - css/showHide: Non-animated
.show()
,.hide()
and.toggle()
; can be excluded if you use classes or explicit.css()
calls to set thedisplay
property. Also removes the effects module. - deprecated: Methods documented as deprecated but not yet removed.
- dimensions: The
.width()
and.height()
methods, includinginner-
andouter-
variations. - effects: The
.animate()
method and its shorthands such as.slideUp()
or.hide("slow")
. - event: The
.on()
and.off()
methods and all event functionality. - event/trigger: The
.trigger()
and.triggerHandler()
methods. - offset: The
.offset()
,.position()
,.offsetParent()
,.scrollLeft()
, and.scrollTop()
methods. - wrap: The
.wrap()
,.wrapAll()
,.wrapInner()
, and.unwrap()
methods. - core/ready: Exclude the ready module if you place your scripts at the end of the body. Any ready callbacks bound with
jQuery()
will simply be called immediately. However,jQuery(document).ready()
will not be a function and.on("ready", ...)
or similar will not be triggered. - deferred: Exclude jQuery.Deferred. This also removes jQuery.Callbacks. Note that modules that depend on jQuery.Deferred(AJAX, effects, core/ready) will not be removed and will still expect jQuery.Deferred to be there. Include your own jQuery.Deferred implementation or exclude those modules as well (
grunt custom:-deferred,-ajax,-effects,-core/ready
). - exports/global: Exclude the attachment of global jQuery variables ($ and jQuery) to the window.
- exports/amd: Exclude the AMD definition.
The build process shows a message for each dependent module it excludes or includes.
AMD name
As an option, you can set the module name for jQuery’s AMD definition. By default, it is set to “jquery”, which plays nicely with plugins and third-party libraries, but there may be cases where you’d like to change this. Simply set the "amd"
option:
1 | grunt custom --amd="custom-name" |
Or, to define anonymously, set the name to an empty string.
1 | grunt custom --amd="" |
Custom Build Examples
To create a custom build, first check out the version:
1 | git pull; git checkout VERSION |
Where VERSION is the version you want to customize. Then, make sure all Node dependencies are installed:
1 | npm install |
Create the custom build using the grunt custom
option, listing the modules to be excluded.
Exclude all ajax functionality:
1 | grunt custom:-ajax |
Excluding css removes modules depending on CSS: effects, offset, dimensions.
1 | grunt custom:-css |
Exclude a bunch of modules:
1 | grunt custom:-ajax/jsonp,-css,-deprecated,-dimensions,-effects,-offset,-wrap |
There is also a special alias to generate a build with the same configuration as the official jQuery Slim build is generated:
1 | grunt custom:slim |
For questions or requests regarding custom builds, please start a thread on the Developing jQuery Core section of the forum. Due to the combinatorics and custom nature of these builds, they are not regularly tested in jQuery’s unit test process.
Running the Unit Tests
Make sure you have the necessary dependencies:
1 | npm install |
Start grunt watch
or npm start
to auto-build jQuery as you work:
1 | grunt watch |
Run the unit tests with a local server that supports PHP. Ensure that you run the site from the root directory, not the “test” directory. No database is required. Pre-configured php local servers are available for Windows and Mac. Here are some options:
- Windows: WAMP download
- Mac: MAMP download
- Linux: Setting up LAMP
- Mongoose (most platforms)
Building to a different directory
To copy the built jQuery files from /dist
to another directory:
1 | grunt && grunt dist:/path/to/special/location/ |
With this example, the output files would be:
1 | /path/to/special/location/jquery.js |
To add a permanent copy destination, create a file in dist/
called “.destination.json”. Inside the file, paste and customize the following:
1 |
|
Additionally, both methods can be combined.
Essential Git
As the source code is handled by the Git version control system, it’s useful to know some features used.
Cleaning
If you want to purge your working directory back to the status of upstream, the following commands can be used (remember everything you’ve worked on is gone after these):
1 | git reset --hard upstream/main |
Rebasing
For feature/topic branches, you should always use the --rebase
flag to git pull
, or if you are usually handling many temporary “to be in a github pull request” branches, run the following to automate this:
1 | git config branch.autosetuprebase local |
(see man git-config
for more information)
Handling merge conflicts
If you’re getting merge conflicts when merging, instead of editing the conflicted files manually, you can use the featuregit mergetool
. Even though the default tool xxdiff
looks awful/old, it’s rather useful.
The following are some commands that can be used there:
Ctrl + Alt + M
- automerge as much as possibleb
- jump to next merge conflicts
- change the order of the conflicted linesu
- undo a mergeleft mouse button
- mark a block to be the winnermiddle mouse button
- mark a line to be the winnerCtrl + S
- saveCtrl + Q
- quit
QUnit Reference
Test methods
1 | expect( numAssertions ); |
Note: QUnit’s eventual addition of an argument to stop/start is ignored in this test suite so that start and stop can be passed as callbacks without worrying about their parameters.
Test assertions
1 | ok( value, [message] ); |
Test Suite Convenience Methods Reference (See test/data/testinit.js)
Returns an array of elements with the given IDs
1 | q( ... ); |
Example:
1 | q("main", "foo", "bar"); |
Asserts that a selection matches the given IDs
1 | t( testName, selector, [ "array", "of", "ids" ] ); |
Example:
1 | t("Check for something", "//[a]", ["foo", "bar"]); |
Fires a native DOM event without going through jQuery
1 | fireNative( node, eventType ) |
Example:
1 | fireNative( jQuery("#elem")[0], "click" ); |
Add random number to url to stop caching
1 | url( "some/url" ); |
Example:
1 | url("index.html"); |
Run tests in an iframe
Some tests may require a document other than the standard test fixture, and
these can be run in a separate iframe. The actual test code and assertions
remain in jQuery’s main test files; only the minimal test fixture markup
and setup code should be placed in the iframe file.
1 | testIframe( testName, fileName, |
This loads a page, constructing a url with fileName "./data/" + fileName
.
The iframed page determines when the callback occurs in the test by
including the “/test/data/iframeTest.js” script and callingstartIframeTest( [ additional args ] )
when appropriate. Often this
will be after either document ready or window.onload
fires.
The testCallback
receives the QUnit assert
object created by testIframe
for this test, followed by the global jQuery
, window
, and document
from
the iframe. If the iframe code passes any arguments to startIframeTest
,
they follow the document
argument.
Questions?
If you have any questions, please feel free to ask on the
Developing jQuery Core forum or in #jquery on irc.freenode.net.