BDD in Action

Theory and Practice of Behavior Driven Development

Transcript

1. BDD in Action Theory and Practice Vladimír Gorej @vladimirgorej
2. Problems • Creating tests concerned with tech. details • Creating tests using TDD with insufficient value • Testing things other 2 amigos don’t care about • No common language for 3 amigos • Misunderstood specifications • Incomplete map of all system features • Not building the right software right
3. TDD 1) Write a failing tests 2) Make the test pass 3) Refactor and clean 4) Repeat the step 3.) until satisfied Focus more on technical details. Avoids manual testing, allows refactors, increase maintainability and confidence of developers.
4. BDD • Builds on TDD • Different naming in unit tests • Starting sentences with should • Focusing on product behavior • Crystal clear intent of the test • BDD tests as absolute minimum • Test description understood by 3 amigos
5. TDD vs BDD
6. BDD practices • Key goal – identify business goal and look for features that delivers the goal • Key activity – slicing user stories into features • Writing specification for these features • Automating the specification
7. Example mapping 1) Write a story 2) Find acceptance criteria (rules) 3) Define every rule with one ore more examples 4) Find the questions about unknowns Goal Turning unknown unknown into known unknown.
8. Example mapping (c) cucumber.io
9. Nomenclature Establish common vocabulary for 3 amigos. Use mind map (lucidchart) to visualize it. Mind map about educational technology (c) Wikipedia
10. Gherkin Plain English with couple syntactical rules that each of 3 amigos can learn in couple of minutes. Each scenario demonstrates an example.
11. BDD Tools Cucumber Will match the text in each step of your scenario to the appropriate test code. Other tools: JBehave, Rspec, SpecFlow
12. Why should I care ? • Living tested documentation of all features • More readable tests = better quality • Focus on things that matters – Features • Reducing costs • Faster releases (no manual testing before release) • Complete 3 amigos confidence • Building the right software right
13. How to start ? • Start trying BDD on your personal projects • Introduce BDD fragments to your daily work • Rewrite existing unit TDD tests into BDD style • Use expectations instead of assertions • Start using Example mapping • Test features, not implementation details • Start using cucumber by delegating to existing tests
14. Thank you! Resources • Learning Behavior-driven Development with JavaScript by Enrique Amodeo • BDD in Action: Behavior-Driven Development for the whole software lifecycle by John Ferguson Smart • 1.5 year of Apiary BDD experience