A Comprehensive Test Strategy for Internet Explorer 6, 7 and 8

David — Mon, 05 Oct 2009 00:06:59 +0000

Test early, test often. Web development demands persistent testing throughout the entire process to identify issues early and deal with them before they require a large-scale overhaul. Internet Explorer (IE) usage is diminishing, yet it remains the predominant browser for most sites. In addition, users of IE do not always upgrade immediately, even when there is a new version with clear benefits over the old. Many IT departments prevent users from upgrading due to a dependence on or a lack of resources to roll-out a new browser and many users simply don’t see a reason to upgrade. Plus, with the recent announcement that Microsoft plans to support Windows XP until 2014, IE6 – the default browser in XP - will be with us for some time. Even the promise of Google Chrome Frame doesn’t let us off the hook because we can assume it won’t be installed for similar reasons. That leaves us with the burden of testing in multiple versions of IE.

In this article, I’ll show you how to install multiple, legitimate versions of IE to speed up testing by taking advantage of two no-cost products available from Microsoft: Virtual PC (VPC) and Internet Explorer Application Compatibility VPC Images. When we’re done, you’ll be able to confidently test in IE6, IE7 and IE8.

While there are various “stand-alone” versions of Internet Explorer available, none are officially supported and I always question their accuracy, especially for anything involving cookies, JavaScript or sessions, so I don’t use them. Fortunately, Microsoft provides free (as in beer) versions of IE in the form of Virtual PC images. You can choose IE 7 or 8 on Vista or XP SP3, or IE 6 on XP SP3. The limitations – such as their limited lifetime – the current images expire January 1, 2010, but new images should be released before then – and additional time to launch are far outweighed by the assurance gained by using the genuine article of an installed version of IE. Plus, you have the option to save or roll-back the state of the machine so it’s a breeze to quickly try out new things such as Google Chrome Frame.

What’s a Virtual Machine?

Good question. Simply put, a system Virtual Machine (VM) is an operating system running within a window on your computer. When launched, a window appears that resembles another computer running on your desktop, taskbar and all. You can resize the window or switch to fullscreen mode and feel like you’re using a different machine. In fact, you don’t have to stop at just using a different browser. A major advantage provided by a virtual machine is the fact that the entire system is sandboxed. Take advantage of that by installing and testing screen reader software or other assistive technology that you may not want to use all the time on your host computer.

The Strategy: Upgrade to IE8, Install IE6 as a VPC

IE8 is a major step forward from IE7 in terms of performance, standards support and development tools. The IE Developer Toolbar add-on for IE6 and IE7 has been renamed Developer Tools and greatly expanded to include a JavaScript debugger and console (similar to the Firebug add-on for Firefox). Plus, the Developer Tools feature is now bundled with the browser by default – this is great news for developers who are not allowed to install add-ons. Like Firebug, you can open the Developer Tools by pressing F12 on the keyboard, or you can select it from the Tools Menu in either the Menu Bar or Command Bar. Personally, I add it directly to the Command Bar by right-clicking an empty area of the toolbar area, selecting “Customize” and then “Add or Remove Commands.”

So go ahead and upgrade to IE8 because of the reasons stated earlier. In fact, IE8 includes a robust IE7 mode called Compatibility View which you can use for testing – it’s accessed by the Developer Tools. So installing IE8 means you have IE7 built-in, which means you just need to install IE6 in a Virtual PC image. Of course, you may want to install a VPC with IE7 just to be sure, but the switching within IE8 is much faster than waiting for the VM to load and allocating space for another VPC (about 1.5GB).

Logistics

Here’s how we’ll do it: we’ll install Virtual PC first and then set up individual virtual machines (VMs). When we’re finished, you’ll be able to fire up a window with an instance of XP or Vista with a “real” (installed) version of IE and test with confidence. Let’s begin.

Here are 3 steps to get your virtual machines set-up:

Download and install Microsoft VirtualPC
Download licensed disk image from Microsoft of Windows with IE
Create a virtual machine inside VirtualPC using the disk image

Here they are again, in detail:

Download VirtualPC
1. install VirtualPC
Download IE Application Compatibility VPC Images
1. Double-click the “.exe” file to expand the image (VHD file, or virtual hard disk) to the location of your choice. Note: these files will be greater than 1GB in size, so choose wisely.
Create Virtual Machine Configuration (VMC) files
1. In the Virtual PC console, click the “New…” button to launch the New Virtual Machine Wizard. The option “Create a virtual machine” should be selected. Click “Next” to continue:
2. Choose where to create the VMC file, which will contain the settings of the VM that loads the VHD. Personally, I prefer to keep it in the same location as the VHD. Click “Next”.
3. Now, we’ll choose the operating system (it should be pre-selected) and review the default hardware selection. Note the low amount of RAM memory (128MB) – we’ll adjust this in the next step. Click “Next”:
4. “Memory” – In this step, I recommend increasing the RAM from the recommended 128MB, so select “Adjusting the RAM” to reveal additional fields to “Set the RAM for this virtual machine.” This virtual RAM will use the physical RAM available on your host machine, so choose a level that you’ll be comfortable with. I recommend at least 512MB RAM if you can spare it and click “Next” to continue:
5. “Virtual Hard Disk Options” use the default selection to use “An existing virtual hard disk” – we’ll use the VHD we expanded in step 2.
6. “Virtual Hard Disk Location” Browse to the location of the VHD file we expanded in step 2. If you choose to “Enable Undo Disks” there will be an additional file created that is about the same size as the VHD file (>1GB) so bear that in mind. Personally, I use my VMs only for testing pages, not storing data, so I do not use this because the VM can save its state when you close it and it takes additional time to commit the changes to the Undo Disk on close.
7. Finally, review your settings in the “Completing the New Virtual Machine Wizard” pane and click “Finish”. Congratulations, now you’re on your way to using your shiny new VM! Once the wizard closes, you’ll see the newly-created VM listed in the Virtual PC Console. You can select it and click “Start” to launch it.

Now we’re ready to launch our new VM. You can launch it in various ways:

Opening VirtualPC, selecting the VM and launching it
Launching the VM directly by opening the VMC file (which will launch VirtualPC and then automatically launch the VM)
Protip: create a shortcut to the VMC file and put it in your Start menu, Quick Tasks toolbar or right on your desktop for easy access.

So go ahead and launch it. Once Windows has booted up, we can start to finalize the setup.

Using Your New VM

Alright, your new VM is ready to use, so let’s set it up. Here are some notes to bear in mind:

Adjust the network settings: You probably need to adjust these settings by going to the Edit menu of the VM window, selecting “Settings” and then “Networking.” If you’re using a laptop, you’ll need to set this each time you switch between wired and wireless networking.
Flash is not installed by default, so you’ll need to install it manually.
On the desktop inside the VM window, you’ll see icons to install the IE Developer Toolbar and the MS Script Debugger. These add-ons have been replaced in IE8 by the much-improved Developer Tools which are included with the browser. You can also install IE7 Readiness Toolkit.
Get the full effect by switching the VM to fullscreen mode in the menu or press Right Alt+Enter.
Copy and paste works only for text between the host computer and the VM, such as copying URLs and such.
The VM acts like a separate machine on your network, so if you want to test pages from your local server (localhost) you’ll need to use your IP address instead.
Got more? Please share them with us in the comments!

Congratulations! You’re all set to test using legitimate, full versions of Internet Explorer on Windows thanks to Microsoft. What are your tips and tricks for using virtual machines and what do you use them for?

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Gov 2.0

A Comprehensive Test Strategy for Internet Explorer 6, 7 and 8

What’s a Virtual Machine?

The Strategy: Upgrade to IE8, Install IE6 as a VPC

Logistics

Using Your New VM