Successful software development depends on effective software testing. And among the various software testing methodologies, automated tests are a useful idea.
Writing extensible automated tests is challenging. You will encounter more and more challenges each time you develop a new test to validate a use case scenario that is more and more sophisticated. You can actually leverage the same software design patterns that we take use of when we create the business logic to make it simpler to manage automated testing. A strategy design pattern is one of these patterns, and it can assist us in writing extendable and highly maintainable programs. You can enrol at the software testing training to learn more.
Other classes are just required to extend the one main interface. The three tiny blocks on the left in the diagram represent the three additional classes that are required to specify the more specialized methods that will be accessible to the context object. Depending on the context, the context object will execute the main strategy (the main class), which will invoke the appropriate sub-strategy.
The interface we’re going to construct will allow us to describe the behaviour of a testing algorithm at runtime when we implement a strategy design pattern.
A Java-based example of how to construct an automated test based on a strategy design pattern is a nice one for you to employ. It’s crucial to use automated testing while creating online projects, and automated testing can be greatly improved if we follow software design patterns.
Implementing Strategy Design Pattern for an Automated Test
Each user type on a website needs to be tested, including the administrator, a brand-new user, and a registered user. Each sort of user can be covered by automated tests that we can create. However, this is a challenge since we’ll be writing a lot of boilerplate code. We must create more specialized tests to validate specialized user rights because each type of user has unique access privileges. What happens then if a new class of user emerges? Do we need to rewrite the test case from scratch? In fact, a strategy design pattern can help us execute tests more effectively.
We will require a fundamental Java interface that will allow us to create automated tests while keeping the strategy design pattern in mind. The main interface will be implemented by this interface, which will be called IValidationStrategy.
The main interface, as we stated in the introduction, won’t actually test anything. For instance, if the method of our IValidationStrategy interface is invoked directly, it may raise an error. In this approach, we alert other developers to the need for them to create their own automated tests for a certain strategy. Essentially, this means that we must develop our own methods for particular techniques (other Java classes).
Two public classes, AdminValidationStrategy and NewUserValidationStrategy, are defined by our interface, IValidationStrategy. The validate() method particular to these interfaces is defined in each of the classes. Undoubtedly, if necessary, an interface can expose additional public methods. Again, the key is to adhere to the idea of strategy design and write all special (i.e., unique) test logic in the appropriate classes (sub-strategies).
The IValidationStrategy must be an ancestor class for the AdminValidationStrategy and NewUserValidationStrategy classes. These classes actually expand the primary interface by adding certain behavior based on which class the context class will call. In these classes, we must redeclare some methods (in our example, the validation() function).
Then there is context, which is determined by the interface of the user validation strategy. In order for the IValidationStrategy class to be able to check the permissions of a particular user, the context object must give the necessary data.
We must create a user (an administrator or a new user) and call the corresponding method (test_user_validation in our example) within the UserValidationContext class.
You don’t need to alter the context (a new user or an admin) in which the code executes if you add a new user role to your application. It is just essential to use the disclosed interface with a new strategy that has been implemented for new functionality.
As the primary test scenario only implements the fundamental logic for all user types, such an approach aids in the reduction of boilerplate code. Additional classes include and test the logic that may change (for instance, when the same type of user may be granted new rights). The Strategy design pattern for automated testing will, in the end, make it easier to support and enhance your automated tests in the future.
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