Testing abstract PHP-class static methods: A guide to using anonymous classes

Описание: Explore effective strategies for testing abstract PHP class static methods, focusing on the use of anonymous classes to create meaningful tests.
---
This video is based on the question https://stackoverflow.com/q/64425849/ asked by the user 'Wolfone' ( https://stackoverflow.com/u/6294605/ ) and on the answer https://stackoverflow.com/a/64427332/ provided by the user 'Philip Weinke' ( https://stackoverflow.com/u/8296334/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Testing abstract php-class static methods that need extending classes to be meaningful

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Testing abstract PHP-class Static Methods: A Guide to Using Anonymous Classes

When it comes to writing tests for abstract classes in PHP, developers often encounter a unique challenge. In our case, we want to test a static method, getConstants, of an abstract class without resorting to a concrete implementation. This scenario poses a significant testing dilemma. In this guide, we’ll explore how to effectively tackle this issue using anonymous classes in PHP.

Understanding the Problem

Let’s break down the situation further:

Abstract Base Class: You have an abstract class, MyAbstractBaseClass, which includes a static method getConstants. However, this abstract class does not define any constant fields itself.

Extending Class: There’s an extending class, MyExtendingClass, which inherits from MyAbstractBaseClass. This class would typically define the constants that we want to test.

Testing Challenge: The challenge arises when we want to test the getConstants method without creating a concrete extension class that implements the constants.

This leads to the question: How can you effectively test abstract class static methods in this context?

The Solution: Utilizing Anonymous Classes

The solution lies in taking advantage of anonymous classes introduced in PHP 7.0. Anonymous classes allow you to create a class instance without formally defining the class, making them perfect for testing abstract class methods. Here’s how to implement it in your tests:

Test Class Implementation

Here’s a simple implementation of an anonymous class to test the getConstants method:

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Tests

Testing With Constants:

In the first test, it_should_return_all_constants, we define an anonymous class that extends the abstract class and declares two constants.

We then call getConstants() and verify that it correctly returns an array of constant names.

Testing With No Constants:

The second test, it_should_return_an_empty_list_when_there_are_no_constants, uses an anonymous class that does not define any constants.

We check that getConstants() returns an empty array, ensuring that the method behaves as expected when no constants exist.

Conclusion

Testing abstract class methods can be challenging, particularly when trying to avoid concrete implementations. However, by leveraging the power of anonymous classes, you can create robust and meaningful tests for static methods. This approach not only simplifies the testing process but also enhances the maintainability of your code.

By incorporating these techniques into your testing strategy, you can ensure that your abstract classes are well-tested without unnecessary complexity. Happy coding!