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Behavior-driven Development

@vgoldin

Intro…

Behaviour-driven development is an “outside-in” methodology. It starts at the outside by identifying business outcomes, and then drills down into the feature set that will achieve those outcomes. Each feature is captured as a “story”, which defines the scope of the feature along with its acceptance criteria.

BDD yet another *DD???

Bridge the gap between business outcomes (i.e. capabilities) and code

establish common understanding of scope, between business folks, the analyst, the developer and the tester

make acceptance criteria executable

From the Vision to the CodeVisio

n

Goal

Cap

ability

Feat

ure

Story

Scen

ario

Code

* every level focuses on certain aspect

What makes a good Story?

Should follow the INVEST principle:

Independent

Negotiable

Valuable

Estimateable

Small

Testable

User Story and BDDUser Story = Business Outcomes

Acceptance Criteria = Scenario*

Test Case = Executable Scenario (i.e. behaviour)

* — Is not replacement for conversion. Is the result of conversation.

* — Scenario is a example of specification by example

The structure of the story

Title (one line describing the story) Narrative: As a [role] I want [feature] So that [benefit] Acceptance Criteria: (presented as Scenarios) Scenario 1: Title Given [context] And [some more context]... When [event] Then [outcome] And [another outcome]... Scenario 2: ...

TDD => BDD

Test => Behaviour

Testing => Verifying Behaviour

Obvious starting p0int

JBehave

…

…

…

…

Demo

Hidden benefits…Unambiguous acceptance criteria

Clean User Stories

Impact delivery vs. feature delivery

Team collaboration improves domain knowledge

Awesome code coverage

No waste in code

Don’t let your process hide your ignorance!

Referenceshttp://jbehave.org/

http://dannorth.net/introducing-bdd/

http://dannorth.net/whats-in-a-story/

http://gojko.net/2013/09/30/writing-as-a-user-does-not-make-it-a-user-story/

http://impactmapping.org/delivering.php

http://specificationbyexample.com/key_ideas.html