When it comes to mobile app development, there’s one thing every app developer knows but doesn’t always want to admit: bugs are inevitable. App development isn’t something that one can get right in the first go no matter how skilled or experienced you are.
That’s where unit testing comes in—your secret weapon to ensure your app doesn’t just work but thrives under pressure. In this guide, we’ll break down the art and science of writing effective unit tests for you or your app development team to create apps that are reliable and solid in the long run.
Why is Unit Testing Even Required?
Let’s get one thing straight: unit testing isn’t just a “nice-to-have.” It’s a must. If you were to launch your app with poorly conducted unit testing, there’s gonna be some serious criticism coming your app’s way. It’s essentially like shipping a car without checking if the brakes work.
The Cost of Skipping Unit Tests
It doesn’t take a lot to imagine what it would look like if you skipped a highly crucial and important step of app development. Your app would be riddled with bugs and technical errors, which will heavily affect the overall experience for users.
And we all know what happens when customers aren’t satisfied, as an app developer or app development agency, you not only lose ratings and reviews but also your credibility and your reputation takes a toll along with the trust of your users.
Unit tests are your first line of defense against these nightmares. They allow you to catch bugs early, often before they even make it into the codebase.
The ROI of Unit Testing
In the mobile app development business, time is money. Meeting deadlines is a nightmare in it of itself and writing unit tests might seem a bit time-consuming but it wouldn’t compare to the hours, if not days of debugging afterwards when everything is set and done.
Tweaking and solving problems in the code at hand is way faster as you have a defined and relatively smaller parameter to work with. It also helps to scale and maintain a code that has been thoroughly tested
The Ins and Outs Of Unit Testing
Not all unit tests are created equal as you can’t just slap on the same unit test for every code. There is a specific science for successful unit testing. Luckily it’s not that hard to learn but writing effective tests still requires a mix of technical know-how and strategic thinking. Here’s how you can do it right.
1. Keep It Isolated
Testing one function at a time is the way to go. If you’re testing a function that calculates the total price in a shopping app, don’t let it depend on external factors like network calls or database queries. There are other tests that can be used regarding dependencies such as integration tests, contrast testing, etc.
2. Make It Readable
Your tests should be as clean and readable as the production code. Using descriptive names for your test methods, like “testCalculateTotalPrice_withDiscount_appliesCorrectly” instead of just “test1” makes it easier for other app developers (or future you) to understand what’s being and what has been tested.
3. Follow the AAA Pattern
Arrange, Act, Assert. This is the golden rule of unit testing that breaks it down into 3 simple and easy steps
Arrange:
Set up the necessary conditions for your test.
Act:
Execute the code you’re testing.
Assert:
Verify that the outcome matches your expectations.
This structure keeps your tests organized and predictable.
4. Test Edge Cases
Don’t just test the happy path. Think about edge cases—what happens when a user enters an invalid input? What if the network is down? A good unit test covers these scenarios to ensure your app can handle real-world chaos.
Steering Clear of Common Hurdles
Even the best of the best app developers oftentimes slip up at the simplest tasks and there’s no shame in revising the basics every now and then. Here are some of the most common problems you might run into while testing your code.
1. Testing Too Much at Once
As tempting as it seems, testing multiple functionalities in a single go to “save time and effort” is the wrong approach. Unit testing should be focused on a smaller parameter that has either one or mutual functionality.
2. Ignoring Test Maintenance
Your tests aren’t, and shouldn’t be recyclable. Write in accordance with the code rather than slapping on a similar old one. Old tests might not fully adhere to the newer code and could potentially give you incorrect results.
3. Relying Solely on Unit Tests
Unit testing isn’t the only tool in your toolbox and solely relying on unit tests isn’t actually enough. Don’t forget about integration tests, UI tests, and manual testing. Utilize every asset you have in order to develop the perfect app.
Wrapping Up: Unit Testing as a Superpower
At the end of the day, unit testing isn’t just about catching bugs—it’s about building confidence. Confidence that your app works as intended. Confidence that you can push updates without breaking things. And confidence that your users will have a seamless experience.
So, the next time you’re tempted to skip writing tests, remember that every great app is built on a foundation of solid, well-tested code. And if you’re looking to create apps that stand out in a crowded market, unit testing is the way to go.
