Test Driven Development: What and Why?

In 2003, Kent Beck invented a development approach that is still considered one of the most progressive, however not widely used. This approach is Test-Driven Development. Experts are still arguing about its significance. The existence of TDD is of particular importance for the QA sphere. Many believe that testing during the product development stage by the developers themselves will soon put testers out of work. This is unlikely. TDD and QA testing are two things that coexist happily together. Let's look at the essence of this approach, its pros and cons.

1. What is Test Driven Development?

Test Driven Development (TDD) is an approach that gives confidence in the work. A set of TDD methods leads to simple software solutions. And any developer can use them. This is what the creator of the approach says.?

But how it works?

The mechanism is:

1. Red stage

??- Create a test for a short snippet of your code.

??- Run it to make sure it fails.

2. Green stage

??- Development of functionality to match the written tests.

??- Run tests.

??- Result — passed "green" test (if not, repeat the green stage).

3. Refactoring

??- Fixing defects in existing working code, cleaning

2. Why should we use Test Driven Development?

“Why use TDD if QA testing exists?” is a very logical question. Let’s have a look at the advantages of Test Driven Development.?

*But remember that these are not the benefits of TDD over QA testing. The use of both is necessary to create a quality product (we will show you this in the next article).

Increased ROI. ?The material and time costs for final testing are reduced if you test each unit during the development phase. This fastens the release of a quality product on the market, so that it can bring you profit.

N.B.! This pro only works in the long run. First implementation of TDD will be costly. And this will not benefit you if you use the approach only for one small product.

Simplification. Designing the test before writing the code allows the developer to delve deeper into the requirements and understand them. In addition, the likelihood that the code will initially be written correctly is much higher. Engineers will only use the correct code in response to the need for the tests they have written. The process of initially thinking about and writing a test causes the programmer's brain to work in reverse: first thinking about how the function will be used and how it can be implemented, and only then how the test should be written.

Comfortable Maintenance. Code maintenance is also simplified. During modifications, interacting with clean code is much easier. TDD is embedded in the development process at a deep level. So, it? is guaranteed that each individual code can be changed without the risk of side effects on other parts of software.?

Fewer bugs. Every respectful testing company strives to provide customers with a bug-free product. But the axiom of testing sounds like "It's impossible to make a product completely bug-free."? With each unit being tested and always keeping in mind that the code must pass the already written test, the bugs of the final product will be sporadic.

Better reporting. No, TDD will not create reports for you. But developers will be able to use them as documentation. There they will see how any component of your code works.

Happiness. It may sound naive and cute, but this is true. According to "Test-Driven Development" by Kent Beck,? when using TDD, programmers are less stressed, trust is increased in teams, and customers begin to look at each new version of the product with enthusiasm.

3. What are the controversial moments of Test Driven Development??

When trying to analyze TDD, we came to the conclusion that there are almost no shortcomings.

Yes, implementation will initially slow down the process and cost money. But in the long run it will all pay off. Your development will proceed quickly. QA testing will not take much time, as some of the work will be done during the development phase.

The disadvantages are more related to the need to train your team:

Necessary to be used by all team members. Now you know how TDD works, so you'll not argue that TDD is meaningless if used by the part of the team. So, you'll have to pay for the training of every employee.?

Boring and hard. The brains of developers are primarily focused on creating. They write code and grow their product like a child. They are unlikely to be interested in the work of a QA tester. Not because it is worse, but because it is arranged differently. Some tasks may seem too monotonous and repetitive. You need to possess a special kind of knowledge, perseverance, and discipline while learning TDD. Developers are stymied in their efforts to learn TDD due to a slew of misconceptions.

Despite the fact that there are so few cons, it can be said with confidence that this approach is very difficult to implement in real life. Many developers will praise TDD, but as soon as we ask if they use it, there will be an awkward silence. The main reason is that the approach is utopian. In general, it's very difficult to write a test that accurately captures all the wishes about a product, and then write the same perfect code. It can turn into permanent changing of both. And it will take a lot of time, effort and nerves.

4. Conclusion

Test Driven Development is a software development process that relies on writing and running tests before, during, and after writing a program. TDD relies on the repetition of unit tests, which means that the developers write tests for each piece of code being developed and run them repeatedly. The tests are designed to ensure that the requirements for the software have been met and that it is functioning as designed. TDD increases ROI, simplifies your development process, leads to eliminating bugs effectively, allows better maintenance and leads to satisfaction from the development process.

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