1. Acceptance Test Driven Development with SpecFlow and Friends
Christopher Bartling
Joel Levandoski

2. Contact information
Christopher Bartling
Joel Levandoski

3. Administrative stuff
Presentation and demo are available on BitBucket.org

4. Topics Acceptance Test Driven Development (ATDD) SpecFlow for .NET
Behavior Driven Development (BDD) tool
WatiN and WebAii
Live demonstration
Questions

5. Acceptance Test Driven Development
ATDD
Acceptance tests are executable specifications of desired behavior and functionality of the system
Expressed in language of the problem domain
Automated
Regression suite
Development is driven from the outside-in

6. ATDD vs. TDD TDD is extremely valuable, but you need more
Achieve great unit test coverage and still not deliver value to the customer
ATDD focuses on complete features and functionality
ATDD: macro view
TDD: micro view

8. SpecFlow for .NET BDD testing framework
Integrates nicely with Visual Studio
Acceptance tests manifest themselves as features and scenarios
SpecFlow generates automated test from features
SpecFlow tests run as normal xUnit tests
Visual Studio test runner, build server

9. Features Describe some piece of functionality of the system
Maintained in a .feature file
Plain readable text
Understandable by all parties, including business
Gherkin format, popularized by Cucumber
Features contain one or more scenarios

10. Feature file example
Feature: Calculate Net Present Value In order analyze the profitability of a project As a project manager I want to be able to calculate the project’s Net Present Value Scenario: A project is rejected Given a project to evaluate When data is entered reflecting a failing project ROI scenario Then the net present value calculator will reject the project

11. Scenarios A scenario describes a single acceptance test for a feature
Most features are composed of multiple scenarios
SpecFlow generates a test for each scenario
The name of the test is generated from the scenario title

12. Scenario example
Scenario: A project is rejected when its NPV is negative Given a project to evaluate When data is entered reflecting a failing ROI scenario Then the net present value calculator will reject the project

13. Scenario steps Used to compose a scenario
Custom code to automate your application
Describe preconditions, triggering action, and verification of outputs for the acceptance test
Given: preconditions
When: triggering action
Then: behavior and state verifications

14. Scenario step example Given a project to evaluate
is matched to the following step definition binding…
project to evaluate")]
public void GivenAProjectToEvaluate() {
. . . }

15. Set up and tear down Attributes for before and after events
TestRun
Feature
Scenario, ScenarioBlock
Step
Specificity achieved when used with tags

16. Tags Markers that can be applied to features and scenarios
Useful for selectively mixing in behavior
Used to categorize scenarios
Some unit test frameworks support this categorization tagging
Custom tags you define

17. Tag example
@WatiN Scenario: Save valid sample size mid range Given the user enters 10 as sample size When the user selects save Then the value is stored

18. Tag example used with BeforeScenario
[BeforeScenario("WatiN”)] public void BeforeScenarioUsingWatiN() { ... }

19. Background Common preconditions for all scenarios in a feature
Contains one or more scenario steps
Executed before any other steps in the scenario
SpecFlow generates a method from the background element in the feature file in the test class
Invoked from each scenario test case in the test class

20. Background example
Background: Given that the welcome page is displayed Scenario: Add a comment to a book being reviewed . . .

21. Scenario outlines Data-driven scenarios or scenario templates
Consists of
Scenario template specification with data placeholders
Set of examples providing values for placeholders
SpecFlow generates parameterized test logic for the scenario outline and individual test method for each example set

22. Scenario outline example
Scenario Outline: Score calculation tables Given a new bowling game When I roll the following series: <rolls> Then my total score should be <total score> Examples: | game | rolls | total score | | beginners game | 2,7,3,4,1,1,5,1,1,1,1,1,1,1,1,1,1,1,5,1 | 40 | | one single spare | 2,8,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 | 29 |

23. ScenarioContext ScenarioContext.Current.Pending()
Causes the step definition to return pending
Used to signal a stubbed step definition
ScenarioContext.Current dictionary
Allows you to carry context/state across step definitions participating in scenario

24. WatiN Open source browser automation tool for IE and Firefox
Similar to Selenium, WebDriver, Watir
Browser abstraction
Find elements using CSS selectors
Interact with AJAX web elements
Handle popup dialogs (native and HTML)

25. WebAii Browser automation tool from Telerik HTML element wrappers
Automates both web 2.0 and Silverlight applications
HTML element wrappers
WaitForElement(s) support when using AJAX
Identifying elements using LINQ
Invoke JavaScript directly from test code

26. Best practices Write high-level specifications
Specifications should remain stable over time
Build a scripting interface for manipulating your system under test (SUT)
Focus specifications on isolated behaviors
Think of specifications in Given-When-Then format
Use the Page Object pattern

27. Smells Specifications are constantly changing
Specifications are composed of “sequential command executions”
Specifications have a lot of instrumentation or fixture code
Specification examples exhibit same structure

28. Net Present Value Calculator Demo
Used in capital budgeting
Measures the excess or shortfall of cash flows, in present value terms, once financing terms have been covered
Demo has two implementations
ASP.NET MVC
Silverlight

29. Questions?

30. Literature cited http://www.concordion.org/Technique.html
tools/webaii-framework-features.aspx
bjects