Acceptance Test-Driven Development (ATDD)

Acceptance Test-Driven Development (ATDD) is a collaborative software development approach where acceptance test criteria are defined before development begins. It ensures alignment between stakeholders, developers, and testers by focusing on the expected behavior of the system.

Key Aspects of ATDD

• Collaboration-Driven – Involves developers, testers, and business stakeholders to define test cases before implementation.
• Requirement Validation – Ensures that acceptance tests align with business and user expectations.
• Early Defect Detection – Identifies issues at the requirement stage, reducing costly fixes later.
• Improves Test Coverage – Facilitates the creation of comprehensive test cases that directly reflect requirements.

ATDD Workflow

1. Define Acceptance Criteria – Stakeholders and teams define clear, testable acceptance criteria.
2. Write Acceptance Tests – Test cases are created based on the defined criteria.
3. Develop Code – Developers write code that meets the predefined tests.
4. Run Tests – Automated or manual tests are executed to validate functionality.
5. Refactor & Improve – Code is refined until all acceptance tests pass.

Example of ATDD in Practice

Scenario: User Login System

• Acceptance Criteria:

  • The user must enter a valid email and password.
  • The system must return an authentication response within two seconds.
  • If credentials are incorrect, an error message must be displayed.

• Acceptance Test (Before Development):

  • Given a registered user with valid credentials
  • When they enter their email and password
  • Then they should successfully log in and be redirected to their dashboard.

• Development & Testing:

  • Code is implemented to satisfy the acceptance test.
  • Tests are executed, and the feature is refined until all tests pass.

Why ATDD Matters

• Aligns Development with Business Goals – Ensures that software meets real-world needs.
• Enhances Collaboration – Encourages shared understanding between business and technical teams.
• Reduces Rework – Catches issues early, preventing costly fixes later in the development cycle.
• Supports Agile & DevOps – Fits seamlessly into iterative development and continuous testing practices.

See also: Acceptance Criteria.