Validating Site Analytics

Almost every modern company with an e-commerce presence makes decisions with the help of site data and analytics. The questions posed surrounding a user base can be almost endless. Which pages are people viewing? What marketing campaigns and promotions are actually working? How much revenue is being generated and where is coming from?

In an environment where data is valuable and accessible, it’s important to take a step back and ask the question: is this data accurate? If the data Brad Pitt was basing decisions on to run a baseball organization in the movie Moneyball wasn’t correct, then it would’ve been an extremely short movie (if not somewhat comical). Ultimately, the analytics collected from our websites and applications are used to make important decisions for our organizations. When that data turns out to be inaccurate then it becomes worthless, or worse yet, negatively impacts our business.

Throughout my professional career I have noticed ensuring the integrity of this data can often be put on the backburner within individual software teams. Sure, it’s one of the most important things to leadership, but in our day-to-day job we are often focused on more visible functionality rather than the one network call in the background that is reporting data and doesn’t have anything to do with our apps actually working. At the end of the day, if this data is valuable to our leaders and organization, then it should be valuable to us.

Let’s look at an imaginary business scenario. Say we have a site that sells kittens. Our site sells all kinds of kitten breeds. Our Agile team been working on the site for a long time and feels pretty good about our development pipelines and practices. The automated testing suite for the site is robust and well maintained, with lots of scripts and solid site coverage.

Then one day we find out that Billy from the business team has been doing user acceptance testing on our Adobe Analytics once every couple months. He’s got about 200 scripts that he manually goes through, and he does his best to look at all the really important functionality. But wait a second… we know that our site records data for about 100 unique user events. What’s more, there are about 200 additional fields of data that we are sending along with those events, and we are sending data on almost every page for almost every significant site interaction. This could easily translate into thousands of test cases! How could we possibly be confident in our data integrity when we are constantly making changes to these pages? How in the world is Billy okay with running through these scripts all the time? Is Billy a robot? Can we really trust Billy?

This new information seems like a potential quality gap to our team, and we wonder how we can go about automating away this effort. It definitely checks all the boxes for a good process to automate. It is manual, mundane, easily repeated, and will result in significant time savings. So what are our options? Our Selenium tests can hit the front end, but have no knowledge of the network calls behind the scenes. We know that there are 3rd party options, but we don’t have the budget to invest in a new tool. Luckily, there’s an open source tool that will hook up to our existing test suite and won’t be hard to implement.

The tool that we’re talking about is called Browserup Proxy (BUP), formerly known as Browsermob proxy. BUP works by setting up a local proxy that network traffic can be passed through. This proxy then captures all of the request and response data passing through it, and allows us to access and manipulate that data. This proxy can do a lot for us, such as blacklisting/whitelisting URLs, simulating network conditions (e.g. high latency), and control DNS settings, but what we really care about is capturing that HTTP data.

BUP makes it relatively easy for us to include a proxy instance for our tests when we instantiate our Selenium driver. We simply have to start our proxy, create a Selenium Proxy object using our running proxy, and pass the Selenium Proxy object into our driver capabilities. Then we execute one command that tells the driver to create HAR files containing request and response data.

from the BUP GitHub page at

Since we will be working with HAR files, let’s talk about what those actually are. HAR stands for “HTML Archive”. When we go into our Network tab in our browser’s Developer Tools and export that data, it’s also saved in this format. These files hold every request/response pair in an entry. Each entry contains data such as URL’s, query string parameters, response codes, and timings.

HAR file example from using Google’s HAR Analyzer
HAR entry details example

Now we can better visualize what we’re working with here. Assuming we’ve already collected our 200 regression scenarios from Billy the Robot, we should have a good jumping off point to start validating this data more thoroughly. The beauty of this approach is we can now hook these validations up to our existing tests. We already have plenty of code to navigate through the site, right? Now all we need is some additional code to perform some new validations.

Above we mentioned that our site is using Adobe Analytics. This service passes data from our site to the cloud using some interesting calls. Each Adobe call will be a GET that passes its data via the query parameters. So in this case we need to find the call that we’re looking to validate, and then make sure that the correct data is included in that call. To find the correct call, we can simply use a unique identifier (e.g. signInClickEvent) and sort through the request URLs until we find the correct call. It might be useful to use the following format to store our validation data:

Data stored in YML format

Storing data this way makes it simple and easy to worth with. We have a descriptive name, we have an identifier to find the correct request, and we have a nice list of fields that we want to validate. We can allow our tests to simply ignore the fields that we’re not specifically looking to validate. Our degree of difficulty will increase somewhat if we are trying to validate entire request or response payloads, but this general format is still workable. So to review our general workflow for these types of validations:

  1. Use suite to instantiate Proxy
  2. Pass Proxy into Selenium driver
  3. Run Selenium scripts as normal and generate desired event(s)
  4. Load HTTP traffic from Proxy object
  5. Find correct call based on unique identifier
  6. Perform validation(s)
  7. (optional) Save HAR file for logs

Not too bad! We can assume that our kitten site probably already has a lot of our scenarios built out, but we just didn’t know it before. There’s a good chance that we can simply slap some validations onto the end of some existing scripts and they’ll be ready to go. We’ll soon be able to get those 200 UAT scripts built out in our suite and executing regularly, and Billy will have a little less work on his plate going forward (the psychopath).

In my opinion, it’s a very good idea to implement these validations into your test automation frameworks. The amount of value they provide compared with the amount of effort required (assuming you are already running Selenium scripts) makes this a smart functionality to implement. Building out these tests for my teams has contributed to finding a number of analytics defects that probably would’ve never been found otherwise and, as a result, has increased the quality of our site’s data.

A few notes:
– We don’t necessarily want to instantiate our Proxy with every Selenium test we run. The proxy will consumer additional resources compared to running normal tests, but how much this affects your test box will vary depending on hardware. It is recommended that you use some sort of flag or environment variable to determine if the Proxy should be instantiated.
– It can seem practical to make a separate testing suite to perform these validations, but with that approach you will have to maintain practically duplicate code in more than one place. It is easier to plug this into existing suites.
– BUP is a Java application that has it’s own directory and files. The easiest way to manage distribution of these files is to plug it into version control in a project’s utility folder. There is no BUP installation required outside of having a valid Java version.
– I wanted to keep this post high level, but if you are using Ruby then there are useful gems to work with Browserup/Browsermob and HAR files (“browsermob-proxy” and “har”, respectively).

Happy testing!

Additional References:

Browserup Proxy
Browsermob Proxy Ruby gem
HAR Ruby gem

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