Common Challenges In Selenium Automation & How To Fix Them?
Original Source: LambdaTest
Selenium is one of the most popular test frameworks which is used to automate user actions on the product under test. ?Selenium is open source and the core component of the selenium framework is Selenium WebDriver.
Selenium WebDriver allows you to execute test across different browsers like Chrome, Firefox, Internet Explorer, Microsoft Edge, etc. The primary advantage of using the Selenium WebDriver is that it supports different programming languages like .Net, Java, C#, PHP, Python, etc. You can refer to articles on selenium WebDriver architecture to know more about it.
Though Selenium makes a website or web-app testing simple, there are a fair number of challenges in Selenium automation that developers face while using the framework. Let’s have a look at some of the most common challenges faced In Selenium Automation, along with their resolution.
False Positives & False Negatives(Flaky Tests)
False positive is a scenario where your test result comes out to be successful, even though when it is not. Vice-versa, False negative is a scenario where the test results report an error with a script execution, even though everything is working as intended. False positives & False negatives have always posed a challenge for web automated testing, and Selenium is no different.
When you are running hundreds or thousands of test cases through your Selenium script then there may be a chance where you encounter such flaky tests which show false positives or false negatives. If left unhandled for long, flaky tests may end up leaving a tester with a deluded image of their automation test scripts or web application under test.
Flaky tests are certainly one of the most common challenges in Selenium automation. They could be tricky to manage, and I would love to elaborate some ways through which you can deal with test flakiness, but that would be a detailed discussion in itself. I will be covering an entire article around handling flaky tests soon. Stay tuned for that by hitting the notification bell.
Not So Scalable Approach
Selenium is a great automation testing tool, and being open-source it has helped make life easier for web testers around the world. However, one of the major challenges in Selenium automation is the inability to scale.
The ultimate goal of performing automation testing is to cover more test coverage in less time. Initially, you may have short test builds, however, your product is bound to expand with every sprint. This would mean you may need to cover a larger number of test cases. Using Selenium WebDriver, you could only perform testing in a sequential way and that won’t be as effective as you may want your automation process to be. Also, the speed at which tests will be executed would depend upon your computing speed.
Now, we know that is where a Selenium Grid comes to aid by empowering you to run test cases in parallel. But there is a downside to that as well. You cannot thoroughly test your website or web-app across multiple combinations of browsers + OS. Why? Because your Selenium Grid would only help to execute cross browser testing on the specific browsers that are installed in your local machine.
LambdaTest provides a cloud-based Selenium Grid to help you paddle faster through your release cycles. You can test your web-app or website on more than 2000 real browsers, browser versions and operating systems on the cloud.
Instead of linear testing, you can leverage the power of Parallel testing in Selenium, through which you can reduce overall project costs, accelerate product/feature delivery as the automation tests are executed in Parallel (i.e. concurrent sessions).
Handling Dynamic Content
A website or web application may consist of static content or content that is dynamic in nature. Testing a website or a web application that has static content poses a minimal number of challenges in Selenium automation. However, in today’s times, most of the websites contain content that that may vary from one visitor to another. That implies that the content is dynamic in nature (AJAX based apps).
For example, an e-commerce website can load different products based on the location from where the user has logged in or content may vary depending on what the user has selected from a particular drop-down menu. As the new content takes time to load, it is important to fire your test only when the loading is complete. Since elements on a web-page are loaded at different intervals, there might be issues if an element is not yet present in the DOM. This is why handling dynamic content has been one of the most common challenges in Selenium automation.
One easy solution to solve this problem is putting the thread to sleep for a couple of seconds which may give sufficient time to load the content. However, this is not considered a good practice, because, irrespective of whether the required event occurs or not, the thread would sleep for that much time duration.
A better approach to handle this challenge with Selenium WebDriver dynamic content would be to use Implicit Wait or Explicit Wait (depending on your requirement).
Explicit Wait For Handling Dynamic Content
Using an explicit wait, you can make the Selenium WebDriver halt the execution & wait till a certain condition is met. It can be applied along with thread.sleep() function if you wish to set a condition to wait until an exact time period. There is a number of ways in which explicit wait can be accomplished, WebDriver with ExpectedCondition is the most popular option.
In the example above, two searches are performed on the URL under test https://www.lambdatest.com. The first search is for the element home-btn where an element is located via CLASS_NAME for a maximum duration of 10 seconds. Check out our blog, if you are not aware of how to use Locators in Selenium WebDriver.
The second search is for a clickable element login for a maximum duration of 10 seconds. If the clickable element is present, a click() action is performed. In both cases, WebDriverWait is used along with ExpectedCondition. 500 milliseconds is set as the default limit for which the ExpectedCondition gets triggered by the WebDriverWait, until a successful response is received.
Some of the common Expected Conditions are below:
Implicit Wait For Handling Dynamic Content
Implicit wait informs the WebDriver to poll the DOM for a certain time duration in order to get the presence of web element(s) on the page. The default timeout is 0 seconds. The Implicit Wait requires an effort of a one-time setup, when configured properly, it would be made available for the lifetime of the Selenium WebDriver object.