Debugging Techniques for Selenium Test Scripts

Debugging Techniques for Selenium Test Scripts

Automation testing is not always a piece of cake. Writing and maintaining the automation test code can be tricky and tedious. There are possibilities where the test code would not work as expected. This might lead to false negative or false positive results. In such cases, debugging the test code is the only way out! 


Debugging helps in pinpointing errors and understanding the control flow in the code. It is an adequate method to understand the execution flow. Additionally, debugging helps to understand the test failures and discover the root cause of the failures. Debugging issues in tests can pose a greater challenge when the test suite comprises several test methods. 


Selenium has gained significant attention and widespread adoption in the automation tool market. Its open-source nature and compatibility with multiple programming languages and browsers have contributed to its immense popularity among users. Like any other software, Selenium test scripts can also encounter errors and bugs that hinder the automated testing process. 


Here are a few debugging techniques that can help in identifying and resolving errors and failures in Selenium test scripts: 


Identifying Common Errors in Selenium


One of the pivotal challenges software testers face when working with Selenium is identifying and resolving common errors during test script execution. These errors range from element not found exceptions to synchronization issues and unexpected pop-ups. Testers must thoroughly understand the Selenium framework and its various components to troubleshoot and debug these errors effectively. 


Investigating user error messages and logs, analyzing web elements attributed to the identified problem, and using internal debugging utilities can help identify a source for the failure, enabling necessary corrections. Moreover, it is essential to be updated with the recent Selenium updates and best practices so that testers can draw beyond errors in advance, aided by this automated testing software.


Debugging with Logging Utilities


Logging utilities assist developers in outputting a variety of logs according to the target. If there are any issues with the test scripts, logging can be enabled to identify the precise location of the problematic code.


Log4j logging is a Java-based open-source framework that can be used for logging purposes by importing the maven dependency. Here are the various components of Log4j:


Loggers: Loggers possess all the information about the logging level. It offers diverse severity levels for logs. The first step is to develop an object of the Logger class: 

Logger logger = Logger.getLogger(“ClassName”);

Furthermore, there are seven types of severity log levels that Logger furnishes:

  • All
  • Info
  • Debug
  • Warn
  • Fatal
  • Error
  • Off


Appenders: The logs generated with the severity above log levels must be transmitted to a destination to access and view. Appenders carry out this task. The appenders are responsible for directing the log events to the designated destination folder or printing them on the console based on the specified configuration. There are three types of appenders to output the logs:

  • Rolling File Appender
  • ConsoleAppender
  • FileAppender


Layouts: Layouts furnish different methods for formatting the logs. The logging data can be formatted in various formats with the below-provided approaches:

  • Public static Logger getLogger (String name)
  • Public static Logger getRootLogger()


Using Breakpoints for Efficient Debugging


Breakpoints authorize testers to pause the execution of the script at specific points to inspect the current state of variables, objects, and the application under test. Testers can closely examine the program flow and identify any unexpected behavior or errors by strategically placing breakpoints at critical junctures, such as before a problematic function or after a specific action.


When a breakpoint is triggered, the Selenium test script halts its execution. This allows testers to step through the code line by line, observing the values of variables and the actions performed on the application. Further, this facilitates a comprehensive comprehension of the code’s execution path and aids in identifying the precise location of any potential issues.


Utilizing breakpoints, the testers discover crucial information on how their Selenium test scripts operate under various conditions to expedite troubleshooting and locate causes of errors. This approach, alongside other debugging methods such as logging and handling of errors, gives testers the power to troubleshoot, thereby ensuring the stability of automated tests.


Using Local Testing 


The easiest way to validate the script is by executing it locally on your machine. If the automated tests run on a cloud platform or remote devices like Loadero, extra manual interference, and visual validation could hint at where the issue might lay. 


The script must run in the same environment as the remote device. This ensures that there are no errors because of inconsistencies in the configuration. It is essential to ensure that you pay close attention to the following aspects when commencing the debugging process of your test script during local testing. 


Utilizing Console Logs for Troubleshooting


Console logs are a powerful tool for capturing and analyzing the internal workings of the script during execution. By strategically inserting console.log statements at key points in the code, testers can output relevant information, such as variable values, function outputs, or error messages, to the console output. 


This facilitates a real-time view of the script’s behavior and assists in identifying any unexpected or erroneous execution paths. By carefully examining the console logs, testers can gain valuable insights into the script’s execution flow, helping to identify and resolve issues efficiently.


Debugging Element Identification Issues


Debugging element identification issues is a common challenge encountered while working with Selenium test scripts. These issues arise when the script fails to locate and interact with the desired elements on a web page. To tackle this problem, testers can employ several debugging techniques. 


One method to ensure the accuracy of element locators is by examining the HTML structure of the webpage and confirming that the locators align with the anticipated elements. If the locators are correct, testers can check if any dynamic elements or timing issues are causing the failure. They can implement waits or synchronization techniques to confirm that the elements are loaded before interacting with them. Besides, testers can use browser developer tools to inspect the elements, their attributes, and CSS properties, which can furnish insights into why the element identification is failing. 


Handling Synchronization Problems in Automation


Synchronization issues arise when there is unsynced timing between the script run and page appearance or absence of elements. These problems can result in test failures and faulty findings. To manage synchronization problems, testers can implement various techniques. 


One approach is to use explicit waits, which allow the script to pause for a specified period until the desired element becomes available. Another technique is to employ implicit waits, which set a global timeout for all elements, allowing them to load before interacting with them. Furthermore, testers can utilize the fluent wait concept, where the script waits for a specific condition to be met within a defined time frame. 


Capturing Screenshots


Usually, when the regression or smoke test suite is executed, the testers do not observe the execution for extended hours. Hence, they would want to know where the test case failed exactly. This will help them take the necessary steps to resolve the issue. 


One potential solution that can be employed to address this issue is to capture a screenshot of the webpage at the precise moment when the test script encounters a test script failure. This will help the testers to identify where the test method failed easily. 


Selenium furnishes an interface TakesScreenshot that can capture screenshots of web pages. The ITestResult interface can be utilized to obtain the execution result or status of the test method.


Incorporating Exception Handling for Stability


Exception handling is another important aspect of ensuring stability in Selenium test scripts. The exceptions are unexpected errors or events that may happen during script uploading and can obstruct the continuity of automation. By implementing exception-handling strategies, testers can manage such unexpected errors in a structured manner that prevents the script from abruptly terminating and provides an environment for more stable testing.


One widely utilized method for managing exceptions is through try-catch blocks. The code that may generate an exception Within the try block is enclosed. If an exception occurs, it is caught by the catch block, authorizing testers to handle the exception gracefully. This can incorporate logging the error details, taking screenshots for further analysis, or implementing alternative actions to recover from the error and continue with the test execution.


Besides the try-catch blocks, Selenium also features a set of predefined exception classes that testers can use to handle particular exceptions. For instance, the NoSuchElementException class can capture errors if a web element is not found on such a page. With the proper handling of these exceptions, testers can be assured that their script will remain running effectively despite unexpected errors.


Leveraging Cloud Testing Tools and Frameworks


Cloud testing tools and frameworks provide a virtual environment that authorizes testers to run their tests on multiple browsers and operating systems simultaneously. This makes it easier to identify any issues or inconsistencies across different platforms. By leveraging the power of the cloud, testers can save time and effort by eliminating the need to set up and maintain physical testing environments. 


Moreover, cloud testing tools like LambdaTest involve advanced debugging capabilities like real-time logs, screenshots, and video recordings that help to provide appropriate insight into the root causes of the failure in the test scripts. 


LambdaTest is an AI-powered test execution and orchestration platform that empowers developers and testers to perform automation testing seamlessly on over 3000+ real browsers and operating system combinations.


With these tools at their disposal, it becomes easy to identify and rectify any errors that could have occurred during automation testing.


Despite the best efforts to carefully craft test cases, there is always a possibility of encountering failures that result in false positives or negatives. Utilizing the right method to debug these failed test cases becomes necessary to leverage automation test scripts. By applying the approaches discussed in this blog, you can effectively troubleshoot and resolve any issues that may arise in your test scripts. Remember to pay attention to details, use the available tools, and continuously test and monitor your scripts to ensure smooth automation testing. 

TDPel Media

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