DEV Community

Cover image for Boost Your Python Unit Tests: A Beginner's Guide to Abstraction ๐Ÿš€
Retiago Drago
Retiago Drago

Posted on • Updated on

Boost Your Python Unit Tests: A Beginner's Guide to Abstraction ๐Ÿš€


Introduction ๐ŸŒŸ

Hello! I am currently on my journey to understand the powerful tool that is unit testing in Python. I recently came across an enlightening tutorial from, which provided a great starting point. However, as someone new to this field, I noticed a few areas where things could potentially be made more efficient. So, let's dive into it!

Note: I've recently gained new knowledge about unit testing, and I'm excited to share it with you. Please consider that the information below represents my current understanding, which may evolve over time. I'll continue to update and refine this post as I learn more about the intricacies of unit testing. Your understanding and patience are greatly appreciated.

Python Test Fixtures Example ๐Ÿค–

Consider a BankAccount class that we used for our first exercise:

Bank Account class:

We set up our original test class for the BankAccount as follows:

This certainly works, but can we do better? Yes, I believe we can. Here's how we can improve this:

  1. Avoid unnecessary object deletions: In our tearDown methods, we are currently setting the objects to None. However, Python's garbage collection would automatically handle the deletion of objects that are no longer in use. Thus, we could focus more on ensuring that your tests are independent and do not share mutable state to avoid unexpected side effects.

  2. Replace direct answers with calculated results: Instead of using hard-coded values for assertions, using calculations or variables can make our tests more robust and adaptable to changes. This approach allows for flexibility when modifying your code in the future.

My suggestion:

Indeed, one can enhance their unit tests further by incorporating helper functions, especially when dealing with complex arithmetic operations. Helper functions improve the readability of your code and make it easier to maintain. However, be mindful that overuse of helper functions for simple operations like addition and subtraction could potentially convolute your code more than clarify it. The goal is to strike a balance between readability and simplicity, ensuring that your test suite remains straightforward and easy to understand, maintain, and debug.

Transitioning from our BankAccount example, let's dive into a more complex scenario to illustrate this concept effectively.

Abstracting Arithmetic Operations for Better Testing ๐Ÿคš

Let's look at Heron's formula, a method for calculating the area of a triangle, which involves a blend of arithmetic operations such as multiplication and subtraction. This is a scenario where abstracting the arithmetic operations into helper functions can shine and significantly improve the readability and maintainability of your code. Here's how it could look:

And here's the corresponding test class with helper functions:

In this case, using helper functions to abstract the arithmetic operations makes the assertions easier to read. Also, since Heron's formula involves both multiplication and subtraction, having separate functions for these operations increases the readability of the test_area method.

And yes, one of the benefits of this approach is composability. For example, the semi_perimeter function is used as part of the area function, and this is reflected in the tests as well. This enhances the maintainability of the test suite, as changes to the computation of the semi-perimeter would only require updates to the semi_perimeter and area tests, not the perimeter test.

Conclusion ๐Ÿคโœ…

Unit testing is a critical instrument in any software development process, and becoming proficient at it is indeed an ongoing journey. The insights I've shared today are inspired by my own beginner's perspective, a fresh viewpoint that often brings unique value to seasoned developers. It is my hope that sharing this journey from a junior's perspective can shed light on new insights for more seasoned coders and also prove valuable to those just starting their journey in writing Python unit tests.

Remember, it's advisable to steer clear of unnecessary object deletions in your tearDown methods - Python's garbage collection handles this efficiently. Also, consider replacing hard-coded values with calculated results to enhance the flexibility and resilience of your tests, making them better suited to adapt to future changes. This practice of ensuring your tests are robust, adaptable, and maintainable is integral for efficient unit testing and overall quality software development.

As a beginner in unit testing, I hope my insights can help others who are also starting their journey in writing Python unit tests. I am always looking to improve my skills and welcome feedback and suggestions in the comments section below. Let's learn and grow together!

Follow me on Beacons for more Python and software development insights.

ranggakd - Link in Bio & Creator Tools | Beacons

@ranggakd | center details summary summary Oh hello there I m a an Programmer AI Tech Writer Data Practitioner Statistics Math Addict Open Source Contributor Quantum Computing Enthusiast details center.


Top comments (0)