{"id":4339,"date":"2017-03-29T17:00:08","date_gmt":"2017-03-29T17:00:08","guid":{"rendered":"https:\/\/www.ckl.io\/?p=4339"},"modified":"2022-09-21T18:19:14","modified_gmt":"2022-09-21T18:19:14","slug":"tdd-mobile-dev-matter-timing","status":"publish","type":"post","link":"https:\/\/cheesecakelabs.com\/blog\/tdd-mobile-dev-matter-timing\/","title":{"rendered":"TDD on mobile dev, a matter of timing"},"content":{"rendered":"\n

When we start the development of a product, there is always a desire to make it as perfect as possible: fulfilling the client’s expectations, offering a good learning opportunity to the developer, and delivering a system with high maintainability and scalability.<\/p>\n\n\n\n

As the code base grows, keeping it problem-free becomes a harder challenge. Testing manually each module of the application can take so much time that developers may become unproductive.<\/span><\/p>\n\n\n\n

To solve this issue, automatic test technologies have evolved a lot.<\/span><\/p>\n\n\n\n

They… well\u2026 run automatically. Tests are an additional set of software that developers write to test its own code and ensure the expected outcome.<\/span><\/p>\n\n\n\n

If you do a quick research about software testing, you may face some recurrent terms like <\/span>unit tests, integration tests, TDD (Test Driven Development) <\/span><\/i>and <\/span>BDD (Behavior Driven Development).<\/span><\/i><\/p>\n\n\n\n

The first two are types of tests while the others are software development processes. Let\u2019s go through these concepts for those who are not familiar with them.<\/span><\/p>\n\n\n\n

Unit Tests<\/strong><\/span><\/h2>\n\n\n\n

It is a type of automatic test focused on small units or pieces of software, like a method, subroutine or small snippets of code. <\/span><\/p>\n\n\n\n

As very specific tests, usually they are simpler, quicker, and don\u2019t take too much time to be written. Another important aspect is that each test must be individual \u2013 testing only one thing at a time.<\/span><\/p>\n\n\n\n

Integration Tests<\/strong><\/span><\/h2>\n\n\n\n

When creating a big software project, it\u2019s only natural to split it into modules\/submodules. These components must be able to communicate with each other, that is, they must be integrated.<\/span><\/p>\n\n\n\n

To ensure that the integration is working properly, automated tests may be written.<\/span><\/p>\n\n\n\n

These kinds of tests allow developers to find problems in more complex structures, where a simple unit test may not be enough.<\/span><\/p>\n\n\n\n

What is Test Driven Development<\/strong><\/span>?<\/h2>\n\n\n\n

TDD is a process where a test is developed to set a <\/span>definition of done <\/span><\/i>before the actual code implementation.<\/span><\/p>\n\n\n\n

One important thing to keep in mind is that TDD is built upon unit tests, but doing unit tests is not the same as having development driven by tests.<\/span><\/p>\n\n\n

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\"TDD\"<\/figure>\n<\/div>\n\n\n

It consists of three basic steps (Red-Green-Refactor cycle):<\/span><\/p>\n\n\n\n

  1. Write a test that will fail<\/b>: this should happen because the actual implementation code has not yet been created;<\/span><\/li>
  2. Code just the bare minimum to pass the test<\/b>: this will keep the developer focused and provide clarity on what should be implemented;<\/span><\/li>
  3. Refactor the code<\/b>: improve performance and readability. The new code must not fail the test.<\/span><\/li><\/ol>\n\n\n\n

    This is why it is called TDD: because the test drives the development, not the other way around. This has a dramatic impact on how the software is crafted.<\/span><\/p>\n\n\n\n

    Behavior Driven Development<\/strong><\/span><\/a><\/h2>\n\n\n\n

    BDD means to have tests describing behavior that the user can expect from the system. It emerged from TDD and is an extension of it, in the sense that development is driven by behavioral tests.<\/span><\/p>\n\n\n\n

    It uses natural language constructs (English-like sentences) to express the desired behavior and expected outcomes.<\/span><\/p>\n\n\n\n

    It consists of three sections:<\/span><\/p>\n\n\n\n

    1. Context<\/b>: the initial state<\/span><\/li>
    2. Event<\/b>: some action that the user performs<\/span><\/li>
    3. Outcomes<\/b>: expected results<\/span><\/li><\/ol>\n\n\n\n

      Let’s see a brief example to clarify these concepts:<\/span><\/p>\n\n\n

      \n
      \"bdd_example\"<\/figure>\n<\/div>\n\n\n

      These tests may be written before, during, or after creating the implementation code. When before, they guide the development, leading us to BDD.<\/span><\/p>\n\n\n\n

      Benefits of Tests<\/span><\/h2>\n\n\n\n

      Among many of the benefits offered by a good suite of tests, we may cite:<\/span><\/p>\n\n\n\n