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Thiago Pacheco
Thiago Pacheco

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TDD in Practice: Tips and Best Practices for Success

Test-Driven Development (TDD) is a software development methodology that involves writing tests for your code before writing the code itself. This might seem counterintuitive at first, but TDD has a number of benefits that make it an essential part of any software development process.

Here are a few tips and best practices for practicing TDD in your software development projects:

Write small, focused tests

When writing tests for your code, it's important to keep them small and focused. Each test should test a specific aspect of your code, and it should only include the minimum amount of code necessary to make the test pass. This helps you ensure that your tests are thorough and complete, and it also makes it easier to debug any issues that may arise.

Write tests before writing code

One of the key principles of TDD is to write tests before writing code. This helps you identify the specific requirements and expectations of your code before you write it, which can help you design and build better software. It also helps you catch and fix any issues with your code early in the development process, which can save you time and effort in the long run.

Test for both positive and negative scenarios

When writing tests, it's important to test for both positive and negative scenarios. This means testing for cases where your code is expected to work correctly, as well as cases where it is expected to fail. This helps you identify any potential issues with your code and ensures that it is robust and reliable.

Use test-driven development in combination with other testing methods

TDD is just one part of a comprehensive testing strategy. It is best used in combination with other testing methods, such as integration testing, end-to-end testing, and continuous integration. By using a combination of these methods, you can ensure that your software is thoroughly tested and of high quality.

Make testing a part of your development process

Testing should be an integral part of your software development process and TDD can help by ensuring that tests are a mandatory step. Make sure to allocate sufficient time and resources for testing, and make sure that your development team is trained in TDD best practices. By making testing a priority, you can ensure that your software is of high quality and meets the needs of your users.

In conclusion, TDD is a valuable tool that can help you design, build, and maintain high-quality software. By following these tips and best practices, you can effectively implement TDD in your software development projects and reap the benefits of this powerful methodology.

Latest comments (6)

axibord profile image
Aghiles Lounis

Depends a lot on the project, not all projects can use TDD/BDD........effectively, it is good especially when you know exactly the requirements/needs, and have clear vision and goals

nietzscheson profile image
Cristian Angulo

In which cases is not effective to use TDD?

pacheco profile image
Thiago Pacheco

I found that TDD is not very effective in cases like:

  • Product that is not supposed to live long, like landing pages and automation tools for example;
  • cli and scripting tools are usually not very effective to be built with TDD;
  • POCs;

I found that apps that are not very interactive may also be worthless to built with TDD, but this and all of the cases above vary a lot based on your current situation.

Another important thing is that trying to learn TDD by applying in your current job is also very complicated. Starting with TDD requires a lot of effort in the beginning and that will definitely slow you down and it may make you give up on this practice. My suggestion in this case is to start learning with personal projects first and slowly start including it in your main job routine.

pacheco profile image
Thiago Pacheco

Totally agree Aghiles.

Learning how to balance the use of testing is also a very important skill to develop.
If you are simply working on a prototype or something that won't live very long it could be unnecessary to use TDD or even write tests at all.

That said, adding TDD as a common practice in my routine was a powerful advantage that helped me develop a better testing mindset. It made me think more about little steps to deliverables and find better solutions, even if I don't write tests I am still constantly approaching development with it in mind.

axibord profile image
Aghiles Lounis

"It made me think more about little steps to deliverables and find better solutions" I agree with that it makes you write offensive tests rather than defensive only.

But I want to know what you think about a project or a feature in a BIG project which is not a common one, but serious project, that is hard to test because we don't know how we should do it, what tools to use, what's the solution, how we can optimize it...etc Would you still use TDD ? For me it's a big No because you don't even know what to write in the test, you are still figuring out something (idk if i'm clear haha^^)

I know for example that lot of features at Netflix can't use TDD at all because of that, and what they do is once the feature is done and they are happy with the result, they write very smart defensive tests and maybe offensive if it's possible, but the main goal is to eliminate regressions, which is still one of the main goals of TDD, being sure that when code is changing it's not breaking something done in the past

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pacheco profile image
Thiago Pacheco

To be very honest, this case you suggested is actually the type of thing I would strongly try to rely on TDD. The reason behind it is that it would force me to first understand the problem completely and clearly define what I am trying to achieve before writing random code.
Working on a large codebase is definitely challenging to apply TDD, but it is completely possible and that will even help you to discover places that you can refactor and decouple.
In terms of tools it is actually very simple. It is not so much about the tools you use, but more about the practices you follow. The way I like to approach it is by having a very general conversation about what needs to be done and list what is the expected behaviour of the feature I need to work on.
For example, you could use an outside-in approach where you first list some scenarios like: "given an input X expect output Y".
Or you could follow and inside-out approach, where you focus first in the core domain of what you are building and start expanding (works wonderfully with DDD btw).

In the end, these suggestions are not the only possible path to a successful career and they strongly depend on the environment that you work on, your style of work and if you really like it or not (which you can only know after trying lol).