NIX/WIN/WEB

I recently installed Internet Explorer 9, and while the browsers interface seems nice, the JavaScript performance in terms of running FormBoss leaves something to be desired: In short, it’s completely unusable.

This was not at all the case in IE 8, and when you consider IE 9 was supposed to be the release that finally fixed JavaScript this is quite disheartening.

As any serious JavaScript programmer can attest to, the irony of IE has always been that in many ways its been more ‘correct’ in terms of standards than the other browsers. That is, what passes in Firefox in terms of JavaScript code fails in IE not because IE is wrong, but because Firefox is so forgiving (and by extension, wrong). This is doubly true when we add a JavaScript library like Prototype JS into the mix, in that the libraries attempts to smooth over browser differences may expose us to subtitle differences in core JavaScript behavior.

On that springs to mind is how some Prototype JS objects property counts are handled. In Firefox an object may be shown to have a length of 1, but in IE that same object had a length of 2. Another example, if memory serves, had to do with valid names of objects. IE has always been more strict in terms of using names that start with numbers, and so on.

Such differences can be hard to spot in production code, and almost always leads to hours of careful testing and debugging.

Thus, as part of my own production process I’d like to share two links that may help you determine if such issues reside in your code or the browser/library begin used.

Google Labs Sputnik JavaScript Test

http://sputnik.googlelabs.com/

This test is very interesting to me as it confirms, among other things, that IE 9′s JavaScript engine is generally more ‘correct’ in terms of standards that the competition. For example, when run in IE 9 I get 71 failed tests, whereas Chrome Canari generates 136 and Firefox 4 181.

In almost all of the cases that ‘fail’ we see the failed test is something the casual JavaScript author may easily do.

For example, in test s12.5_A9_T1 we check for a function declaration within an ‘if’ statement:

// Copyright 2009 the Sputnik authors.  All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/**
* @name: S12.5_A9_T1;
* @section: 12.5;
* @assertion: Function declaration within an "if" statement is not allowed;
* @description: Declaring function within an "if" statement;
* @negative;
*/

if (true) {
    function __func(){};
} else {
    function __func(){};
}

testCompleted();

Have I ever done this? No. Could I see others or even me late at night? Sure. The point being that as you peruse some of the test that say, Firefox 4 fails, it becomes obvious that many of the failures stem from Firefox being ‘fast and easy’ with some of the rules, which ironically, can make creating JavaScript code easier.

Framework Library Test

http://dante.dojotoolkit.org/taskspeed/

This test highlights the differences in the major JavaScript libraries. Of core importance to me are the functions that manipulate the DOM, such as append, insertbefore, insertafter, and so on.