mako-taco / degrade.js

Hacks up Chrome's JS to behave like older browsers, so you don't have to waste time developing for IE

degrade.js

If you want browser compatability back to IE7 or IE8, your dev cycle probably looks something like this:

1. Develop feature in chrome
2. Test feature in chrome
3. Work out bugs in chrome
4. Launch Windows VM
5. Test feature in IE
6. Work out bugs in IE
7. Repeat

If you're writing a third-party library, you can't rely on tools like Modernizr or polyfills to address compatability concerns. That's where degrade comes in. Instead of trying to monkey-patch old browsers to behave sort of like new ones, we make the new browsers as crappy as the old ones by crippling javascript in creative ways.

The result is a development cycle that looks more like this:

1. Develop feature in chrome
2. Test feature in chrome
3. Work out bugs in chrome
4. Repeat

Degrade lets you develop in chrome, but catch IE specific errors before you ever have to open a VM.

Usage

parseInt('010'); //10
degrade.to.ie8();
parseInt('010'); //8, and a warning

You may also pass in an options object:

var options = {
	console: {
		strategy: 'alert',
		logLevel: 'trace'
	}
};
degrade.to.ie8(options);

Options

Below are the complete list of options which can be passed to degrade.

console

Control the behavior of methods like console.log or console.time.

strategy

Must be one of 'alert','error','remove'

Completeness

IE8

• Uses ES3 array prototype
• parseInt with leading 0s defaults to octal
• Object.defineProperty throws an error if passed a non HTMLElement
• Object.getPropertyDescriptors throws an error if passed a non HTMLElement
• Many options to suit your individual needs for console statements

Known issues

1. Event.prototype - In IE8, Event.prototype is essentially empty. It will take a large amount of work to knock down Event, KeyEvent, MouseEvent, etc to IE8s level. This is planned for the future.

IE7

Work on IE7 is planned, but has not yet been started