Acceptance Test Driven Development

Test-driven development (TDD) is an agile approach in which test cases are written before your code has been developed. In a nutshell, you start with failing test cases (red), which pass (turn green) when you work on your code. So, at the end of the development cycle, you ensure that the feature you built covers the requirements defined in the test cases.

For example, if you were building a calculator, you’d start with a failing test case for addition, expecting 2 + 2 to be 4. If your code works, your tests will light up in green, and you will know your feature works.

Acceptance test-driven development (ATDD) is an extension of TDD. It uses the ultimate acceptance criteria for the tests, ensuring that the software meets the overall requirements and expectations of the stakeholders.

What is Acceptance Test-Driven Development?

Acceptance-test-driven development (ATDD) is a software development methodology that encourages all project stakeholders, including developers, testers, and business owners, to collaborate and create an enhanced TDD process. ATDD ensures that application requirements are clear and understandable for all stakeholders. Once finalized, these requirements are transformed into acceptance tests.

Goals of Acceptance Test-Driven Development

It’s clear that collaboration is a key aspect of ATDD. But, apart from that, there are several goals of ATDD:

1. Ensuring requirement clarity

ATDD improves communication between stakeholders, developers, and testers by defining clear and shared acceptance criteria. This ensures that all team members have a common understanding of what the software should do from the user’s perspective.

2. Reducing defects early

ATDD helps identify and fix defects early in the development process by writing and running acceptance tests before the implementation begins. This helps prevent defects rather than just detect them afterward.

3. Aligning development with business goals

ATDD ensures that each feature meets the stakeholders’ expectations by clearly defining the requirements. Ultimately, it helps compile effective acceptance criteria that can be translated into effective test cases.

4. Creating effective documentation

Following ATDD creates great documentation that grows as your product features grow without an effort. It makes it easier to maintain the app as the documentation is always in sync with real business requirements, ensuring traceability between requirements, acceptance tests, and the implemented code.

5. Enhancing test coverage

ATDD increases test coverage by writing acceptance tests for all key features and scenarios.

How do you do Acceptance Test-Driven Development?

Since you now understand the importance of acceptance test-driven development, let’s discuss how you can get started with ATDD in your organization. Here are the eight simple steps you need to follow to start ATDD in your organization:

Step 1: Gather the team

Start by bringing together everyone involved in the project-developers, testers, product owners, and other stakeholders. This ensures that everyone is present for all requirement-related discussions and helps everyone stay on the same page.

Step 2: Define acceptance criteria

Discuss what the feature or functionality should do from the user’s perspective. Together, write down the acceptance criteria. This should be clear, and you must include specific conditions that must be met for the feature to be considered complete.

Step 3: Write acceptance tests

Before you start coding, write acceptance tests based on the criteria.

These tests describe how the feature should behave in various scenarios. Use simple, understandable language or a tool like Cucumber with Gherkin syntax, which reads almost like plain English.

For example, an acceptance test could look like this:

Feature: User Login
  As a registered user
  I want to log into my account
  So that I can access my personal dashboard

  Scenario: Successful Login
    Given I am on the login page
    When I enter a valid username and password
    And I click the login button
    Then I should be redirected to my dashboard
    And I should see a welcome message

These can then be converted to test cases in your codebase using frameworks like Cucumber or simply Jest.

Step 4: Run the tests (they will fail)

Run the acceptance tests right away. At this point, they will fail because the code to implement the feature has yet to be written.

This failure is expected and sets the development stage. Once you start developing your feature, the test cases will turn green!

Step 5: Develop the feature

Now, you can write just enough code to make the acceptance tests pass. This ensures that the development is focused on meeting the specific criteria defined earlier.

Step 6: Run the tests again

After the development, run the acceptance tests again. The goal is for all the tests to pass, showing that the feature works as intended and meets the acceptance criteria.

Step 7: Refine and iterate

If any tests fail, refine and rerun the code until they all pass. This might involve fixing bugs or adjusting the implementation to better meet the criteria.

Step 8: Review and repeat

Once all the tests pass, review the feature with the stakeholders to confirm it meets their expectations. Then, move on to the next feature and repeat the process.

Concluding Thoughts

ATDD is not difficult to understand. It focuses on gathering your team together to discuss the end requirements, which help translate them into meaningful acceptance criteria that you can leverage to build effective test cases that guarantee the feature is done right!

I hope you found this article helpful.

Thank you for reading.