Functional Testing with Selenium WebDriver: A Beginner’s Guide

Functional testing is one of the most essential processes of software development in which the software application must function as expected and fulfill the stipulated requirements. Selenium WebDriver is one of the most effective and flexible tools for testing web applications. This beginner’s guide will introduce you to Selenium Functional Testing. But first, let’s have a look at what is Functional Testing with Selenium WebDriver!

What is Functional Testing?

Software testing, which verifies the functionality of a software system or application, is called functional testing. It ensures that the system acts according to the specified applicable requirements and matches the business requirements.

Functional testing aims to verify the system’s functions, capabilities, and interactions with other components. It entails verification of inputs and outputs, data manipulation, user interactions, and the system response to different circumstances and scenarios. Functional testing simply validates that a system functions as planned.

Types of Functional Testing

Functional testing is software testing that provides the system’s functionality by performing component testing against specified requirements. There are different functional tests, each checking the software functionality in other respects. Some common types of functional testing include:

Unit Testing

Developers usually implement it to realize a unique functionality in a particular application unit. It ensures that each module in the web application functions properly during unit testing.

The functional tests get extra help from unit tests in that they can locate elements that lead to an outage. However, finding the bugs earlier in the process is always preferred, as it becomes harder to diagnose the failed tests as a whole. Unit tests are one of the very automated functional testing types, and developers mostly write these tests to ensure that these units are not full of bugs. If you perform testing early in the software development cycle, you will deliver your product faster with better quality.

Smoke Testing

The process of smoke testing is done after any new software release to check the web application’s fundamental working. The application’s most crucial components and functionality are addressed during smoke testing.

In this regard, the testing efforts are not supposed to be exhaustive but must ensure that the primary functionality of this application is correct.

A smoke test makes the web application stable and reliable only when it passes. Testers can then perform functional tests for the new features added and undertake regression testing using the scenario.

Nevertheless, if smoke testing fails, it implies that the current release is unstable and hence requires fixing.

Regression Testing

Regression testing is carried out to confirm that new code, enhancement, or feature does not negatively impact web app functionality. Also, regression testing is mainly done to discover defects that might have crept into the build under test due to adding new features and functionalities.

For example, you can work with a visitor management system whose recent release included a new feature that generates a report on all the visitors based on one of the categories they belong to. After you carry out smoke testing for this release, you would then regression test it to check if the code from the old release does not introduce any new bugs.

The testers usually experience a challenge regarding regression testing, which might be costly and tiresome. It can be resolved by simply migrating to test automation. You can not only automate your repeatable tests but also scale them to grow test coverage with the assistance of Selenium Grid.

Sanity Testing

Sanity testing means the change in the new build has addressed the issues without having extra bugs. Also, Sanity and smoke testing are often confusing since their names sound similar.

However, the testing between both of these is relatively minimal. The smoke test verifies the overall end-to-end functionality of a web app, and sanity test verifies just new functionalities of a web app.

Integration Testing

Integration testing verifies that the modules of an application do not have bugs while being integrated.

Functional commands and data are integrated into a system with integration tests rather than separate components. In general, it is done to check issues with UI operations, operating timing, API calls, data formats and database access.

System testing

This testing system checks the entire integrated application to assess its compatibility with the set specifications. It is done after the integration testing is carried out. It is not realized by the testers involved in making the application; instead, it is done by individual testers.

It is an essential aspect of functional testing that checks whether the application fits the operational, business, and practical requirements.

Cross Browser Testing

You may think that when your application is ready to launch, it will function the same way on all platforms. However, it’s not always so because every browser renders its app differently depending on its engine.

For instance, if your web app runs smoothly in Chrome, it does not mean it will function the same way when using other browsers such as Firefox, Internet Explorer, etc. Cross Browser Testing is a practice that ensures that a web app works correctly across.

This is how you can be sure your users will experience the same browsing of your application no matter their browser or device. It is usually conducted once your application is completed and is being prepared to enter the market. It is possible to use various tools for automated browser testing in the market.

One notable tool for automated cross-browser testing is LambdaTest. LambdaTest is an AI-powered test orchestration and execution platform that lets you run manual and automated tests at scale with over 3000+ real devices, browsers, and OS combinations. It provides virtual machines with all the browser versions to ensure extensive test coverage.

LambdaTest has features like screenshot testing, live interactive testing, and responsive testing and can be integrated with popular test automation frameworks. The platform makes it easy for users to resolve cross-browser compatibility issues, leading to a seamless web experience for end-users.

In brief, cross-browser testing is crucial in web development to ensure a uniform user experience in different browsers and devices. LambdaTest is one of the many testing tools that help developers carry out thorough cross-browser tests and contribute towards the success and reliability of web applications on increasingly varied web browsers.

Advantages Of Automated Functional Testing

Automated functional testing is vital for faster software release cycles, as it verifies that the software is bug-free and ready for release. It provides developers with multiple benefits, such as:

• Enable the delivery of quality goods in which end-users requirements are satisfied.
• Ensures the developed software does not have bugs and that all application functionalities work fine.
• It improves the overall security and safety of the application.
• It helps minimize the risks and losses of the web app/software product.

Automated Functional Testing Steps.

There are numerous steps involved in the automated functional testing of a web app, such as:

1. Identifying the functional elements of the web app that should be tested, including basic usability, accessibility, main functions of the application, and the error conditions.
2. Determining the main components of testing that will serve as the input data when creating the input data for functionality testing.
3. Identifying the predicted output of the functionality based on the input data.
4. Implementation of test cases generated for testing.
5. Finally, compare the output with the expected results, and if the outcome is the same as expected, your tests are successful.

Even though the automated functional testing of a web app appears pretty easy to execute, it is not that simple, especially for beginners.

Top Automated Functional Testing Tools

Testers prefer to go for automated functional testing as a way of efficient and faster test execution, but manual testing is possible. Choosing the most appropriate one among the multiple tools available in the market is difficult. Here, we highlight some of the top automated functional testing tools:

LambdaTest

LambdaTest improves testing features, including screenshots, video recording, and live interactive testing. It is a scalable Selenium grid that tests multiple browsers and operating systems simultaneously. These include cross-browser testing, screenshot capture, video recording, live interactive testing, scalability, integration with popular frameworks, and an intuitive interface. LambdaTest is the best choice for this testing because it ensures a reliable user experience by checking application performance across different devices and OS.

Ranorex Studio

It provides a complete automated function testing tool that targets web, mobile, and desktop. The product comes with an in-built Selenium WebDriver for easy use.

Selenium

Selenium is a top Open-source automation tool. It has many features and is adaptable to many testing scenarios. For more information on Selenium, check our elaborated page.

JUnit

JUnit is preferred by businesses that test applications for Java based on unit and system testing.

SoapUI

It is a popular open-source functional testing tool for web service testing. SoapUI is useful for complete testing with supporting protocols, including HTTP, SOAP, and JDBC.

The above-stated tools are significant; however, other automated functional testing tools are on the market. Therefore, perform intensive research before choosing the best tool according to your needs. Selenium remains one of the most preferred tools for functional testing because of its reliability and versatility.

Best Practices for Functional Testing with Selenium WebDriver

Let’s dive deeper into each best practice for functional testing with Selenium WebDriver:

Maintaining a Clean and Organized Test Suite:

• Folder Structure: Group your test cases and suites under a folder system. Organize related test cases and suites in logical directories. As a result, you may have folders for each module or function.
• Naming Conventions: Use appropriate names for your test cases and test suites. Each test has a descriptive name that describes its purpose. Using a standard nomenclature improves clarity.
• Comments: Comment your code for better documentation. Explain the test, any specific conditions or assumptions, and any known issues. This enables other team members to understand and ensure the tests.

Implementing Modular Testing for Scalability:

• Page Object Model (POM): Implement the Page object model design pattern. It includes creating a separate class for each web page or your application’s elements. These classes contain the corresponding page’s functionality and locators, making the tests more readable and maintainable.
• Test Data Separation: Separate test data from test scripts. Use external files to store data or data providers. It ensures that the test scripts are not updated when test data is changed.
• Reusable Functions: Common functionalities and create reusable functions or methods. It also minimizes redundancy in your code and makes it easy to update everyday operations.

Continuous Integration and Automated Testing Pipelines:

• Version Control Integration: Add your test suite to a version control system like Git. It allows team members to collaborate, version control, and store the changes history.
• CI Tools Integration: Set up automated testing pipelines via CI tools such as Jenkins, Travis CI, or GitLab CI. Set these tools to initiate test runs whenever there are modifications to the code base. It ensures that tests are performed periodically and problems are detected early during development.
• Parallel Execution: Run tests concurrently to speed up total test execution time. Alternatively, tests can be run in multiple environments concurrently using the Selenium Grid or cloud-based testing services.

Additional Tips:

• Logging and Reporting: Conduct comprehensive logging to provide thorough details about the test execution. Use reporting tools such as ExtentReports or Allure to generate user-friendly yet insightful reports.
• Environment Configuration: Control environment-specific settings using configuration files or properties. It makes it possible to run the same tests through different environments, for instance, development, staging or production.
• Error Handling: Have effective error detection and handling mechanisms in place. Ensure that temporary issues do not cause test failures and correctly capture and handle the exceptions.

Common Challenges and Solutions

So, let’s explore common challenges encountered in Selenium WebDriver testing and their solutions:

Dealing with Browser Compatibility Issues:

Challenge: Web applications must function across various browsers (Chrome, Firefox, Safari, etc.), and each browser may understand the web elements differently.

Solution:

• Cross-Browser Testing: Perform cross-browser tests to identify any compatibility problems. Selenium WebDriver enables you to test on various browsers to ensure a good user experience.
• Use Browser-specific Drivers: Browser-specific drivers are offered by Selenium WebDriver. Use the correct driver for the browser you are testing for compatibility purposes.

Overcoming Intermittent Test Failures:

Challenge: It is also possible to address intermittent test failures for better reliability.

Solution:

• Retry Mechanisms: Re-execute failed tests automatically.
• Wait Strategies: Use detailed logging and explicit waits.

Handling Asynchronous Operations:

Challenge: Ensure that test scripts are synchronized with asynchronous operations.

Solution:

• Explicit Waits: Tell Selenium to wait until the conditions for continuing are met.
• Expected Conditions: Synchronize with the behavior of the app through conditions such as `elementToBeClickable.`

Dealing with Dynamic Elements:

Challenge: Reliably interact with dynamic webpage elements.

Solution:

• XPath and CSS Selectors: Choose reliable locators that withstand dynamic changes.
• Relative Locators: On the resilience of relative locators in Selenium 4.

Managing Test Data:

Challenge: Make test data setup and cleanup simpler.

Solution:

• Data-Driven Testing: Split the test data from each script.
• Database Transactions: Use transactions for data in clean states.

As a result, Selenium WebDriver testing becomes more efficient and reliable across web application scenarios.

Conclusion

To summarize, functional testing with Selenium WebDriver is highly important for any tester or developer. This article looked into various aspects of functional testing and how Selenium can be used for automated functional testing. Besides this, We looked at functional testing, types of functional testing, their place in strategy, and some examples.

Testers should follow the best practices, deal with common issues, and be aware of future trends in order to achieve maximum effectiveness by using Selenium WebDriver.

Happy Testing!