Functional testing, to ensure that the website is working properly, has achieved deep traction but is still done manually in many instances. Automated testing, that makes the test process easy as well as accelerates it and improves accuracy, has caught on even though it suffers from several shortcomings. Multi-tiered architecture, multiple browsers, and complex web technologies all put a spanner in the works, as does the cost to acquire the tool that facilitates automation.
Selenium, the powerful open-source tool that facilitates automated functional testing, has gained considerable popularity of late since it offers a solution to many of these stumbling blocks. This tool renders pages, executes JavaScript and retrieves webpages in a near replica of human work to check if the website is working as it should across various operating systems and browsers.
Here is a run-down of the reasons why people prefer Selenium to other tools for functional automation testing.
- Resilience
The biggest advantage of Selenium is the convenience that comes from adaptability – it has a unique mechanism that allows the same tool to run on multiple platforms. Selenium supports almost all common Operating Systems including Windows, Linux and Mac and runs on all widely used browsers including Firefox, Microsoft Internet Explorer and Safari. What’s more is that it integrates tightly with these browsers as well. On being installed in the application webserver, Selenium deploys Browser Bot, its JavaScript automation engine to the browser automatically. All this means that Selenium is the tool of choice when it comes to cross browser/ cross platform certification.
Since Selenium is JavaScript-based and runs directly in the browser, it overcomes problems related to testing JavaScript functionality that users of competing tools, such as HttpUnit or CanooWebTest face.
Selenium is resilient enough that it supports multiple languages as well. The tool was first written in Java, but now supports PHP, .Net, Perl, Ruby, and Python as well, meaning that the developer can create the testing framework in the language that is already most widely used within the enterprise. Selenium’s “Remote Control” server allows users to write tests directly within the programming language of their choice, enabling conditional logic within tests, try/catch blocks, and other powerful functionality available only in programming languages.
If nothing else, it can be coded as HTML tables also. Selenium supports a wide range of IDEs, such as Net Eeans or Eclipse, depending on the choice of development language.
Surprisingly, such resilience is unmatched by other comparable test tool covers. Competing tools such as QTP, for instance, run only in the Windows environment and work on only a limited number of browsers and versions, thus forcing users to use VBScript.
- Flexibility
Selenium supports flexible test architecture and is as flexible as it is resilient.
Many testers prefer to keep tests as independent and self-contained as possible for the sake of flexibility and maintainability. This allows them to move tests around, delete them, or refactor them as required. Refactoring tests reduce duplication of the test code and increase the maintainability of the test suite, and including one test inside many others reduces code duplication.
Selenium tests build up a regression test suite for the web layer of the application through the iterations of the agile process. This allows developers to refactor the front-end code without fear of breaking the previous acceptance criteria for the application.
Selenium also supports a suite of tests, and tests for certain iteration can be grouped together in a suite and run sequentially. Users enjoy the flexibility of keeping all of the tests in one suite or grouping tests by story, by iteration, by functionality set or any other way. It is also possible to “tag” tests with multiple tags and group tests into suites based on such tags.
- Ease of Use
Selenium offers an intuitive, user-friendly interface for creation and execution of test suites.
The actual task of writing and maintaining scripts is also very easy. Selenium allows identifying elements using the browser’s DOM object, making it possible to write the test using specific identifiers of the necessary element. There is a standard set of commands such as open (a URL), click (on an element), or type (into an input box), and a set of verification commands that allow the user to specify the expected values or behavior. Selenium makes it easy to perform every browser action including otherwise complex events as onMouseOver and onKeyPress.
Selenium’s open-source nature allows users to write their own extensions, making it easy to create custom actions that do sophisticated manipulations.
The tests run directly in the browser, and the user can watch the tests execute. Each command is highlighted as it is executed, and the assert steps turn red or green to indicate success or failure. At the end, passing tests turn green and failing tests turn red in color, all facilitating easy identification.
- Code Reusability
The Selenium web-testing tool uses simple scripts to run tests directly within a browser. It uses JavaScript and iframes to embed the test automation engine into the browser. This allows the same test scripts to be used to test multiple browsers on multiple platforms.
It is also possible to initiate several concurrent tests with Selenium.
- Easy Add-Ons
Selenium is a powerful tool that covers almost all aspects of functional tests. Several add-on tools increase the scope of Selenium. Selenium IDE (previously known as “Recorder”) allows users to navigate their applications in Firefox and record their actions, forming tests
While Selenium is good at automating functional tests, it is not quite good at generating load, and since it requires a browser it is very difficult to generate multiple virtual users. After starting off with Selenium, and ensuring that the web application is working correctly, move on to JMeter and undertake performance testing.
- Robust Reporting
Selenium has robust reporting capabilities, which allow testers to extract the results of the test and take follow-up action in an efficient manner. It offers detailed test execution results with consolidated summary and error snapshots. It enables automated HTML report generation and emailing of the same to all stakeholders.
- Open Source Nature
Finally, Selenium leverages all the advantages that open-source software provides. Being an open-source project, it has no licensing costs associated with it. In contrast, competing tools such as QTP suffer from high licensing costs. Selenium is still under active development, meaning that there is an army of active contributors in user forums who are eager to roll out patches and usable extensions. For these very reasons, it is easy to customize Selenium as per user request. Selenium allows end-users to write and share extensions or other code modifications, even project-specific ones.
Overall, the popularity of Selenium stems from the fact that it handles most traditional problems encountered when automating functional testing, without adding new ones. As it gains widespread adoption, it gathers even more enthusiasts into its folds, people who develop it further, which in turn increases adoption levels.