An element's child nodes will be gone under certain circumstances in IE (at least 7 & 8)

[timmolendijk]

Consider a test page with a main section as follows:

<div id="main">
    <ul>
        <li>yadda</li>
    </ul>
</div>

And a test script as follows:

jQuery(function($) {
    var $elem = $('#main > ul');
    console.log($elem.children().length);
    module('blub');
    test('yadda', function() {
        console.log($elem.children().length);
});
});

One would expect that this prints two times 1 to the console, which it does in Firefox and Chrome. In Internet Explorer (I've tested 7 & 8) it will print 1 and then 0 though, indicating that the element has somehow been emptied somewhere during starting up test yadda. If I reinforce $elem by putting $elem = $('#main > ul'); in a module setup function, the problem miraculously disappears.

[jzaefferer]

Elements inside the #main element get reset after each test run. The inconsistency across browsers is odd, but fine, as you should rely on any selection that ran outside your current test.

[timmolendijk]

Did you mean "(...) as you should not rely on any selection that ran outside your current test" ?

Okay, that's a workable restriction. But I wasn't aware of it. How is one supposed to learn about it?

[jzaefferer]

Yeah, meant what you wrote.

I need to backport some of the documentation from the jQuery Cookbook chapter on testing to the QUnit documentation.