The following is a list of minimal jsFiddles that can be used as a starting point for creating test cases.
Select the appropriate starting widget / interaction / effect and click "Fork" in the header to get started.

Versions

All test cases are based off the latest build of the master branch in the git repository. These are the files used:

<link href="http://code.jquery.com/ui/jquery-ui-git.css" rel="stylesheet" /> <script src="http://code.jquery.com/jquery-git.js"></script> <script src="http://code.jquery.com/ui/jquery-ui-git.js"></script>

If you need to test with a specific version you can use these files instead. Change the versions numbers in the URL as necessary.

<link href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" rel="stylesheet" /> <script src="http://code.jquery.com/jquery-1.9.1.js"></script> <script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script> //Themes <link href="http://code.jquery.com/ui/1.10.3/themes/black-tie/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/blitzer/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/cupertino/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/dark-hive/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/dot-luv/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/eggplant/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/excite-bike/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/flick/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/hot-sneaks/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/humanity/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/le-frog/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/mint-choc/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/overcast/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/pepper-grinder/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/redmond/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/south-street/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/start/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/sunny/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/swanky-purse/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/trontastic/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/ui-darkness/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/ui-lightness/jquery-ui.css" rel="stylesheet" /> <link href="http://code.jquery.com/ui/1.10.3/themes/vader/jquery-ui.css" rel="stylesheet" />