What are the most common design patterns in QA automation?

1 Page Object Model

The page object model (POM) is a design pattern that encapsulates the web elements and actions of a web page or a web application into a separate class or object. This way, the test scripts do not interact directly with the web elements, but rather with the page objects that represent them. The benefits of using POM are that it reduces code duplication, improves readability, and facilitates code maintenance and refactoring. For example, if a web element changes its locator or behavior, you only need to update the corresponding page object, not all the test scripts that use it.

2 Data-Driven Testing

Data-driven testing (DDT) is a design pattern that separates the test data from the test logic. This means that the test scripts use external sources of data, such as Excel files, CSV files, databases, or JSON files, to provide the input and output values for the test cases. The benefits of using DDT are that it increases test coverage, reduces code complexity, and enables data reusability and flexibility. For example, you can easily add, modify, or delete test data without affecting the test scripts, or run the same test script with different sets of data.

3 Keyword-Driven Testing

Keyword-driven testing (KDT) is a design pattern that uses keywords or commands to define the test steps and actions. The keywords are stored in external files or tables, along with the test data and the locators of the web elements. The test scripts use a keyword interpreter or a library to execute the keywords and perform the corresponding actions on the web elements. The benefits of using KDT are that it simplifies the test creation, enhances the test readability, and supports data-driven testing. For example, you can create test cases by using keywords such as click, type, verify, or select, without writing any code.

4 Hybrid Testing

Hybrid testing is a design pattern that combines two or more of the above design patterns to leverage their advantages and overcome their limitations. For instance, you can use POM to create page objects for your web application, DDT to provide test data from external sources, and KDT to define test steps using keywords. The benefits of using hybrid testing are that it offers more flexibility, scalability, and modularity for your test scripts. For example, you can mix and match different design patterns according to the complexity and scope of your test cases.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?