How can you overcome challenges with test-driven development?

Tests can lie! Tests must validate the right behavior. Tests that pass but don't check for the correct thing can create a false sense of security. To avoid this problem, be sure to: 1. Understand what you're testing. If you're not sure about the desired outcome, your tests will be irrelevant. 2. Consider all the different scenarios, especially the edge/extreme cases. Many bugs come out of these! 3. Use realistic test data - not just dummy integers, strings, etc. 4. Verify your assertions carefully to check whether they match exactly what you want to test. If you follow these steps you can be sure you will have a good set of tests that tell you the truth and give you confidence about your code, making refactoring possible/easier.

Here are the tips I usually give to my team in regards to writing clean tests: - Use ShouldWhen or GivenWhenThen naming templates for descriptive test names - Write tests with no logic. Avoid if-else statements and loops. Any additional logic is a potential surface for bugs in your tests. - Structure your code with the ArrangeActAssert pattern. If each part contains multiple lines of code, consider annotating the parts with code comments - A test should follow the F.I.R.S.T. principle. It should be Fast, Independent, Repeatable, Self-validating and Timely. - Couple your tests to behaviors, and not to code structure - Use meaningful test data to reveal real-life scenarios - Learn and use the test doubles properly to express design intents

Understanding the product/service/feature and its intent helps identify the right tests. Write the tests based on the expected workflow. A simple way to follow is - Given x, when y is performed, the outcome is z. When one think, and writes the tests in this format, the resulting test suite is good.

Test-Driven Development (TDD) does not make you slower. It actually makes you faster in the long run. It helps you to produce well-designed code that is completely covered by high-quality tests. Such code is cheap, easy and risk-free to change. Don't think about the time it takes you to write a test for your code. Instead, think about the time you'll waste if a non-tested functionality breaks. Testing is not expensive. Fixing software bugs is.

TDD has two categories as far as I know. One is Test First Development (TFD) which you have described. In normal TDD or BDD, when delivering the requirements is the high priority and time is less, we need to focus on delivering the business requirements first, we sometimes need to write the application code first, then write test cases to ensure the requirements. In another scenario when the product owner himself is not sure about the exact business requirement, only a draft of the user story is given, we need to work on the app code first because the requirement is not clear and it is impossible to write test cases on unclear requirements. Rather we deliver the POC on the feature first and then incrementally get the requirements clear.

Test-Driven Development (TDD) is done best together with Pair and Mob programming. TDD is a design methodology incorporating continuous analysis of the requirements, designing software, and producing quality test suites. If you do these alone, you will have the best work you can do alone. If you work in a pair or mob, you can do the best work the entire team can do.

Actually in my opinion and from my experience, I found code coverage useful but it can't always give us the desired result because it only shows how much of the application code is covered with the test cases but it doesn't ensure the quality of the tests itself. In addition to configuring continuous testing in the test automation process to populate failed tests, slow running tests, code coverage/analysis reports, I suggest configuring mutation tests in the automation process and put a quality gate on the mutation coverage in the merge/pull request. It will give us proper visualization about how much mutants are present in the app code and how much of the mutants got killed and survived with the tests.

Test-Driven Development (TDD) won't solve all your problems. But it will prevent most of them. While adopting TDD can be challenging, it's worth tackling those challenges to achieve well-designed code. Not using TDD can lead to issues like hard-to-maintain code, untestable solutions, and buggy software. Also, note that TDD - when done well - guarantees ~100% code coverage and behavior coverage. Without TDD there is no such guarantee.

I'd say that TTD is not in all cases about writing your tests first (controversial, I know). Good writers of tests can use the mentality from test-driven development and start with very few tests (if any) while developing/prototyping the initial code and still make the code well-testable. When the code starts to stabilize the developer increases the number of tests, which should reduce the number of wasted work on writing tests that ends up with no purpose.

Despite of the things shared above are related with effective TDD there are a key aspect of it that is often ignored: TDD can be used across different stacks without any problem, therefore, keep in mind that each stack offer specific challenges.

TDD may be overwhelming for Low-Code/No-Code kind of development frameworks, we end up maintaining automated test code than the actual application. Have seen the benefits of TDD for core OOP language based development but challenge arises of the testers skill set. We end up hiring more developers to develop & maintain the automated suite and they seldom have testes perspective.

Tentar escrever um app inteiro aplicando o TDD à risca pode ser meio intimidador, principalmente para os membros mais juniors. Identificar as partes mais críticas a serem desenvolvidas, e aplicar o TDD lá pode ser uma boa forma de começar. Outra coisa importantíssima: tentar isolar efeitos colaterais. É tão mais fácil testar - e aplicar o TDD - quando isso acontece.