Acceptance Test-Driven Design (ATDD) is a method which involves users or customer feedback in the creation of the applications. Automated tests are created at the beginning of the development process when acceptance tests are set up by the performers, making it possible to create a product that fully meets the users’ expectations in terms of functionality. This method promotes simplicity, cooperation and feedback on the ongoing process where it offers a tighter match between the product and the customer.
What is Acceptance Test-Driven Development(ATDD)
- ATDD (Acceptance Test Driven Development) is a development technique that gives emphasis on the end users/customers by making acceptance test cases the foundation of development. This means it focuses on providing the actual required functionality/behavior of the system. In this methodology acceptance test is written from the user’s perspective and test cases are created even before coding starts.
- ATDD is extended on TDD (Test Driven Development) which gives emphasis on developers, testers, and business collaboration and it is a test-first approach. Also, ATDD is very much similar to the BDD (Behavior Driven Development) but there is a small difference between them i.e. BDD mainly focuses on the behavior of the system while ATDD focuses on the actual requirements of the customer.
- Some tools which are used for ATDD are TestNG, Spectacular, FitNesse, EasyB, Concordian, Thucydides, etc.
ATDD Cycle
There are four stages in ATDD (Acceptance Test Driven Development) cycle which comprises Discuss, Distill, Develop, and Demo stages. Let's discuss one by one.
- Discuss - User Story (What the customer need from the product at the end of development)
- Distill - Acceptance tests criteria and Automation (Taking consider into different scenarios and system's behavior during various scenarios)
- Develop - Implementation (Develop the feature by following Test First Development TFD approach until it's success/pass)
- Demo - Prototype model (Provide a demo to the business stakeholders and proceeds with iterations)
The need for Acceptance Test-Driven Development
- To avoid ambiguity in requirements.
- To develop the product smoothly.
- To avoid last-minute changes/modifications.
- To deliver a good quality product.
Key practices in ATDD
- Analyze and discuss the real-world scenarios
- Decide acceptance criteria for various scenarios
- Automate the acceptance test cases
- Focus on development based on requirements.
Benefits of ATDD
- Gives a better clarification on the requirements.
- Faster resolution of problems/issues.
- Improves collaboration between cross-team members.
- More focus on customer needs.
- Acts as a guideline for the entire development process.
- Easier to manage.
ATDD Test Format
The ATDD test format generally follows these principles:
- User Story: The acceptance tests are derived from user stories that define what the customer wants in the particular product.
- Acceptance Criteria: To each user story there are correlated narrower acceptance criteria. These criterial define the state to which the feature has to be developed to work perfectly and be fully functional.
- Test Scenarios: Acceptance criteria: Acceptance criteria are used to define the criteria that are easy to understand and to develop a set of scenarios any situation in which the system needs to be tested.
- Automation: Acceptance tests are also automated to enable integration tests and also for the reasons of the regression tests whereby the new code does not alter the existing functionality.
- Demo: Stakeholders are presented with the feature in order for them to give their opinion and to check whether the development matches their requirement.
ATDD VS TDD
Aspect | ATDD (Acceptance Test-Driven Development) | TDD (Test-Driven Development) |
|---|---|---|
Focus | End-user requirements and acceptance criteria | Internal code quality and functionality |
Test Basis | Tests are derived from user stories and acceptance criteria | Tests are based on code implementation and design |
Test Scope | Broad scope, covering end-to-end user scenarios and business requirements | Narrow scope, focusing on individual components or units of code |
Stakeholder Involvement | High, involving collaboration with business stakeholders and users | Low, primarily involving developers and sometimes testers |
Development Approach | Test-first approach, where acceptance tests are written before coding starts | Test-first approach, where unit tests are written before code implementation |
Automation | Acceptance tests are automated for continuous integration and verification of user requirements | Unit tests are automated to ensure code correctness and prevent regressions |
Conclusion
Acceptance Test-Driven Development expansion or ATDD moves the development process to the next level where user needs are put first as well as their means are aligned with business goals. By having clear acceptance criteria, talking to each other and leveraging the utilization of automated tests, ATDD enables developers to have more transparent and efficient development/implementation cycles and produce better quality of products. This way of design priorities the user requirements and allows for their gradual feedback, which results in creation of software that meets customer needs.