Screen resolution vs Resizing a window in Selenium

The main product I test was designed to follow a responsive web design layout so it could theoretically be used on anything from desktop computers to tablets and smartphones. Practically speaking this means different viewable window sizes (viewport sizes) will result in the browser placing elements of our application in different locations on the screen. When running my selenium acceptance tests I wanted to be able to specify different viewport sizes both locally and remotely on Sauce Labs. While the sizes may not make a difference to Selenium they give me another variable to specify if I so choose to do responsive testing. The examples I found weren’t very helpful so I decided to make my own for both.

Resizing your window. Locally the browser can be resized to a specific width and height by using the resize_to() command. For a window size of 1280×1024 the line of code we are looking for is:

window.resize_to(1280, 1024)

In my selenium-examples repo this code goes into the spec_helper file and looks like @driver.manage.window.resize_to(1280, 1024) as you see on line 20:

If you don’t use a helper spec you can include this code in your setup method or right after you call WebDriver.

Setting screen resolution. Resizing your window works great locally but what if you want to run your tests remotely at Sauce Labs? How do we ensure our screen resolution is large enough to support a larger window size? Luckily Sauce Labs opens their browsers to the maximum window size so all we have to do is set the screen resolution.

According to the Sauce Labs’ configurator we want to use the ‘screenResolution’ method like they show below:

caps = caps['platform'] = 'Windows 8' caps['version'] = '43.0' caps['screenResolution'] = '1280x1024'

If we go back to the example-selenium repo you’ll see I’m actually using caps[“screenResolution”] = ENV[‘resolution’] in the above spec_helper at line 11.

I’m setting a global variable for screen resolution so I can update it in the config_cloud file as I might update other global settings like operating system or browser version. This is important because in some cases, I may have to either adjust the resolution size or in the case of Safari, actually comment it out. For some reason Sauce Labs doesn’t have many resolutions options for Mac OS X, which is a bit annoying. The latest versions of OS X don’t even support resolutions of 1280×1024.

Humans and Machines: Getting The Model Wrong

It seems like one of the more prominent and perpetual debates within the software testing community is the delineation between what the computer and human can and should do. Stated another way, this question becomes “what parts of testing fall to the human to design, run and evaluate and what parts fall to the computer?” My experience suggests the debate comes from the overuse and misuse of the term Test Automation (which in turn has given rise to the testing vs. checking distinction). Yet if we think about it, this debate is not just one within the specialty of software testing, it’s a problem the whole software industry constantly faces (and to a greater extent the entire economy) about the value humans and machines provide. While the concerns causing this debate may be valid, whenever we hear this rhetoric we need to challenge its premise.

In his book Zero to One, Peter Thiel, a prominent investor and entrepreneur who co-founded PayPal and Palantir Technologies, argues most of the software industry (and in particular Silicon Valley) has gotten this model wrong. Computers don’t replace humans, they extend us, allowing us to do things faster which when combined with the intelligence and intuition of a human mind creates an awesome hybrid.

Peter Thiel and Elon Musk at PayPal

He shares an example from PayPal: 1

Early into the business, PayPal had to combat problems with fraudulent charges that were seriously affecting the company’s profitability (and reputation). They were loosing millions of dollars per month. His co-founder Max Levchin assembled a team of mathematicians to study the fraud transfers and wrote some complex software to identify and cancel bogus transactions.

But it quickly became clear that this approach wouldn’t work either: after an hour or two, the thieves would catch on and change their tactics. We were dealing with an adaptive enemy, and our software could adapt in response.

The fraudsters’ adaptive evasions fooled our automatic detection algorithms, but we found that they didn’t fool our human analysts as easily. So Max and his engineers rewrote the software to take a hybrid approach: the computer would flag the most suspicious transactions on a well-designed user interface, and human operators would make the final judgment as to their legitimacy.

Thiel says he eventually realized the premise that computers are substitutes for humans was wrong. People can substitute for one another – that’s what globalization is all about. People compete for the same resources like jobs and money but computers are not rivals, they are tools. (In fact, long-term research on the impact of robots on labor and productivity seems to agree.) Machines will never want the next great gadget or the beachfront villa on its next vacation – just more electricity (and it’s not even smart enough to know it). People are good at making plans and decisions but bad at dealing with enormous sets of data. Computers struggle to make basic decisions that are easy for humans but can deal quickly with big sets of data.

Substitution seems to be the first thing people (writers, reporters, developers, managers) focus on. Depending on where you sit in an organization, substitution is either the thing you’d like to see (reduce costs – either in terms of time savings or in headcount reduction) or the thing you dread the most (being replaced entirely or your work reduced). Technology articles consistently focus on substitution like how to automate this and that or how cars are learning to drive themselves and soon we’ll no longer need taxi or truck drivers.

Why then do so many people miss the distinction between substitution and complementarity, including so many in our field?


Shaping Your Identity as a Tester

On Thursday, June 25, 2015 I presented my first webinar called Shaping Your Identity as a Tester that was based on an earlier article I wrote called Blogging for your Career.

uTest recorded it and made it part of their uTest University series, you can check it out here. I’ve also embedded the video below for easy viewing. The slides are pretty simple. My part lasts less than 30 minutes, the rest of the time is spent answering questions fielded from the 75 or so participants who joined. Check it out:

If you joined the webinar and your question wasn’t answered or if you have any questions after watching it here, feel free to leave me a comment (or contact information) or connect with me (on the right) and I’d be happy to respond!