The Importance of Writing Test Cases and How to Get Started

Many developers avoid writing test cases because they think it’s too hard or they’re just not used to it. But test cases actually keep your application behaving correctly over time. I know it’s a huge change but let me tell you how test cases can actually make your work easier and your code better.

Why Write Test Cases?

1. Find Bugs Early: Tests help you catch problems in your code before they become bigger issues. Sometimes to catch the problems in the code we didn't touch it because the new code impacted it indirectly.

2. Better Code Quality: Writing tests makes you think about how to write better code.

3. Easier Changes: With tests, you can change your code confidently, knowing that tests will catch any mistakes.

4. Code Documentation: Tests show how your code should work, which is helpful for new team members. You have 2 choices write so much documentation or write code comments where things are really complex and good test cases. Anyday most of the good developers(including me) who I know choose the 2nd option.

5. Build Confidence: Knowing your code is tested gives you and your team confidence, speeding up development.

How to Start Writing Test Cases?

The hardest part is getting started. Here’s how to make it easy:

1. Start Simple: Write small, simple tests first. For example, if you have a function that adds two numbers, write a test to check if it gives the correct result.

2. Take Small Steps: Don’t try to write tests for everything at once. Add tests gradually, especially when you work on new features or fix bugs.

3. Test What You Know: Begin with the parts of the code you understand best. This makes it less intimidating.

4. Use Automation: Use tools that automatically run your tests and give feedback quickly. Examples include Jest for JavaScript, JUnit for Java or PyTest for Python.

5. Work as a Team: Make test writing a team habit. Use code reviews to ensure tests are written and learn from each other.

How to Write Your First Test?

1. Set Up Your Tools: Choose a testing tool that works with your programming language. For instance, use Jest for JavaScript or PyTest for Python.

2. Write a Simple Test: Start with a basic function. May be from utility functions or write test cases for hitting an API and asserting the response.

3. Expand Slowly: Once you’re comfortable, write more tests for different scenarios.

4. Refactor Safely: With tests in place, you can change your code and use the tests to ensure nothing breaks.

Normal Complaints I hear & My take

1. No Time: It might feel like you don’t have time to write tests, but they save time by catching bugs early. Still not convinced then all the best for future time going to waste on fixing bugs.

2. Too Complex: Tests might seem complicated at first, but starting with small, simple tests makes it easier.

3. Team Resistance: It can be hard to get everyone on board. Show the benefits through reduced bugs and smoother updates.

Writing test cases is very important for reliable software. Start small, focus on simple parts and make testing a regular part of your work. As you write more tests, you’ll feel more confident in your code, your team will work more smoothly and your software will be more reliable. Happy testing!