Overcoming iOS Testing Challenges: 3 Tips when testing

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Every iOS developer grapples with testing challenges. These roadblocks can emerge from an array of issues such as overcomplicating tests, wrestling with messy code, or uncertainty about the next testing step. The good news? These issues are solvable, and a Test-Driven Development (TDD) approach offers practical answers.

Streamlining Testing with a Behavior-focused Approach

A common trap for iOS developers during testing is to lose themselves in the nitty-gritty. When engrossed in complex code structures, you can overlook the forest for the trees. The antidote? Adopting a behavior-focused approach to testing. This tactic stresses testing what your code should do rather than how it does it. Not only does this simplify your testing process, but it also renders your tests more resilient to changes in your code.

Enhancing Code Quality with Red, Green, Refactor Cycle

Another hurdle is tackling disorderly and chaotic code. Staring at a tangled mass of code, and figuring out a starting point can be intimidating. This is where the Red, Green, Refactor cycle of TDD comes to the rescue. Start by writing a test that fails (Red), then code until the test passes (Green), and finally, refine your code (Refactor). This straightforward cycle is a powerful way to systematically enhance your code quality and minimize bugs.

Navigating Tests with the ZOMBIES Acronym

Lastly, determining what to test next can baffle developers. A handy solution is to structure your testing process using the ZOMBIES acronym. ZOMBIES stand for:

• Zero: Start with a test for a function with no input and a simple output. This is the simplest test case you can think of and often involves a system under test (SUT) that does almost nothing.

• One: Write a test case that handles a simple, single piece of data. For example, you might create a single object or send a single message.

• Many: Now, write a test case for multiple pieces of data. This could involve arrays, lists, or other data structures.

• Boundaries: Write tests that check for boundary conditions. This could include tests for data limits or tests to ensure your code handles exceptional cases correctly.

• Interface: Write tests that check how your code interacts with other parts of your system or third-party systems. This could include things like user input, file I/O, or network communication.

• Exceptions: Write tests that handle exceptional cases. These cases are often related to errors or unusual situations your code needs to handle.

• Simple: Keep things as simple as possible. When coding and testing, strive to create the simplest code that passes the tests. You can always refactor later as you understand more about the problem.

The ZOMBIES acronym provides a structured roadmap to testing, enabling you to concentrate on crucial aspects and streamline your testing process. This heightened efficiency saves testing time and ensures your tests are comprehensive and meaningful.

Conclusion

TDD is more than a methodology; it's a toolkit packed with practical solutions to typical testing challenges. By mastering these strategies, you can boost your code quality, make your testing process more efficient, and ultimately, create better iOS apps. Embrace TDD, and unlock the power of ZOMBIES in your testing journey. Your future self (and your codebase) will undoubtedly thank you.

To get a more detailed understanding and tips about applying TDD in your iOS development, I highly recommend Jon Reid's book available at Quality Coding. It's a resource that every iOS developer aspiring to produce high-quality code should read.

Edit:
TDD with ZOMBIES was invented by James Grenning (one of the signers of the Agile Manifesto).