Created: 2008-04-21 16:58
Updated: 2019-02-26 08:44

MooTools Core

Build Status

Selenium Test Status

This repository is for MooTools developers; not users. All users should download MooTools from


You are welcome to contribute to MooTools! What we ask of you:

a. To report a bug:

  1. Create a jsFiddle with the minimal amount of code to reproduce the bug.
  2. Create a GitHub Issue, and link to the jsFiddle.

b. To fix a bug:

  1. Clone the repo.
  2. Add a spec.
  3. Fix the bug.
  4. Build and run the specs.
  5. Push to your GitHub fork.
  6. Create Pull Request, and send Pull Request.

Do try to contribute! This is a community project.

Building & Testing

Current build process uses Grunt, Grunt MooTools Packager plugin, and Karma related repos.

By default, the build process runs the tests (specs) relevant to the build. To build without testing see the packager build targets.

Building MooTools With Compatibility

This means 1.5.1 that is compatible with: 1.4.6, 1.3.x, 1.2.x, and so on.


grunt compat             # or
grunt packager:compat    # to only build the source

Building MooTools Without Compatibility

This means 1.5.1 without deprecated code in 1.4.6, 1.3.x, 1.2.x, and so on.

'Proceed at your own risk'
See the changelog or the blog related to each version for migrating your code.


grunt nocompat           # or
grunt packager:nocompat  # to only build the source

Advanced Building and Testing

See the Gruntfile and MooTools packager for further options.


# with compat
grunt compat --file=Function    # builds with only Core/Function and dependencies, then tests against specs in Specs/Core/Function
grunt compat --module=Class     # tests against all specs in the Specs/Class *folder* (use --file to limit the build)

# without compat
grunt nocompat --file=Function  # builds with only Core/Function and dependencies, then tests against specs in Specs/Core/Function
grunt nocompat --module=Class   # tests against all specs in the Specs/Class *folder* (use --file to limit the build)

Removing Other Packager Blocks

You'll need to add a specific task to the Gruntfile. See packager's documentation for more examples.

Testing locally

I you want to test your local repo you need just some small steps. Follow these in order:

$ git clone  # clone the MooTools repo
$ cd mootools-core                                     # get into the directory
$ npm install                                          # install de testing tools
$ `npm bin`/grunt test                                 # run the specs!

To test a build in a local browser, you can run the :dev target of that build to start a test server at http://localhost:9876/ and point your browser to it. When you're done testing, pressing Ctrl+c in the window running the grunt process should stop the server.


$ `npm bin`/grunt compat:dev

If the log is too long, or if you want to store it in a file you can do:

$ grunt > logs.txt   # This will create a new file called logs.txt in the local directory

Testing on Travis & Sauce Labs

Every new Build and Pull Request is now tested on Travis and Sauce Labs. You can also open your own free account on Travis and Sauce Labs to test new code ideas there.

Travis testing uses PhantomJS which is a headless browser. When connected to Sauce Labs then it is possible to choose any number of different Browsers and Platforms. You will need in this case to change the login key so it will match your account.

To add new Browsers in Sauce Labs testing you can make changes to Grunt/options/browsers.json:

  • add a new browser to the custom launchers already in the Gruntfile.

     chrome: {
     	base: 'SauceLabs',
     	platform: 'Linux',
     	browserName: 'chrome',
  • add the chosen browser, with the correct builds to .travis.yml:

     		- BUILD='compat'     BROWSER='chrome'

Browsers, Platforms, and More

This test suite is ready for Travis & SauceLabs. You can also run locally.


  • IE
  • Edge
  • Firefox
  • Safari
  • Chrome
  • Opera
  • PhantomJS (headless browser)

More Information

See the MooTools Wiki for more information

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