Selenium is a popular tool for web testing automation and scripting. It allows you to simulate user actions on web browsers and verify the results. But how do you create a Selenium script that is reliable, maintainable, and reusable? In this article, you will learn some best practices for creating a Selenium script for web testing.
Selenium supports multiple programming languages, such as Java, Python, C#, Ruby, and JavaScript. You can choose the one that suits your project needs, preferences, and skills. However, some factors to consider are the availability of libraries, frameworks, and documentation for Selenium in that language, the compatibility with your web application and testing environment, and the ease of debugging and reporting.
I recommend using the same programming language that your product is built with. With that, you can integrate automation in your project and comes with that the powerful and native support for more automation capabilities; for example, direct access to resources or app states etc.
To create effective Selenium scripts for web testing, start by installing Selenium WebDriver and selecting a programming language. Write your script, navigating to web pages, interacting with elements, and incorporating assertions for verification. Handle waits to ensure elements load properly. Organize your code for reusability, employ error handling, and set up logging and reporting. Debug your script and consider integrating it into a continuous integration system for team use. Continuously maintain your scripts as web applications evolve. Selenium offers flexibility across languages and browsers, enabling robust and adaptable web testing automation.
A testing framework is a set of rules, guidelines, and tools that help you structure, organize, and execute your test cases. Using a testing framework can make your Selenium script more consistent, readable, and scalable. Some common testing frameworks for Selenium are TestNG, JUnit, PyTest, RSpec, and Mocha. You can also use a behavior-driven development (BDD) framework, such as Cucumber, SpecFlow, or Behave, to write your test cases in a natural language that can be understood by non-technical stakeholders.
Selenium has been developed through the collaborative efforts of hundreds of volunteers and developers. The primary motivation behind utilizing Selenium is to avoid reinventing the wheel. In the same way, there are already excellent pre-existing frameworks available, such as SeleniumBase with Python and TestNG with Java, which offer very easy setup and excellent documentation. These frameworks are the result of the hard work and dedication of many individuals. Therefore, it is advantageous for us to leverage these resources instead of building a framework from scratch.
The Page Object Model (POM) is a design pattern that abstracts the web elements and actions of each web page into a separate class or object. This way, you can reuse the same code for different test cases and avoid hard-coding the locators and values in your Selenium script. The POM also makes your script more robust and easy to maintain, as you only need to update one place if the web page changes.
The AAA pattern stands for Arrange, Act, and Assert. It is a simple and clear way to structure your test cases in your Selenium script. The Arrange section sets up the preconditions and inputs for the test case, such as launching the browser, navigating to the web page, and entering the data. The Act section performs the actions that trigger the test case, such as clicking a button, filling a form, or selecting an option. The Assert section verifies the expected outcomes of the test case, such as checking the page title, the URL, or the text on the screen.
It's important to follow good coding practices when writing your Selenium script to improve its quality, readability, and performance. This means using meaningful and consistent names for variables, methods, and classes, as well as adding comments and documentation to explain the purpose and logic of your code. Additionally, you should adhere to the coding standards and conventions of your programming language and testing framework. Furthermore, use indentation, spacing, and formatting to make your code more readable. To simplify your code, avoid code duplication and use functions, loops, and conditional statements. Lastly, make sure to use exception handling and logging to handle errors and generate reports.
In my case, we used a python based automation framework and used existing build tools to make code scanning and analysis part of the pipeline. This way we got instant feedback from pylint and sonar about code styles and smells. Also part of our setup was to run automation tests as part of CI CD builds, so developers also got immediate feedback about how their changes affect the application.
Once you have created your Selenium script, you need to run and debug it to ensure that it works as expected and produces the desired results. To do this, you can use breakpoints, watch expressions, and step over commands to inspect the values and flow of your code. You can also use print statements or log messages to display the output and status of your code, as well as assertions or validations to check the actual and expected results of your code. Additionally, test runners or IDEs can be used to execute your script in different browsers and environments, while debugging tools or extensions can be used to inspect the web elements and locators on the web page.
Continuous Integration: Consider setting up a continuous integration pipeline to automatically run your tests on code commits, ensuring that your web application remains stable as you make changes. Maintenance: Periodically update your tests as the web application changes and evolves.