Imagination is more important than knowledge. [A. Einstein] Dr Nic's Cucumber: building a better World (object) How to write helper libraries for your Cucumber step definitions and how to upgrade your support libraries from Cucumber 0.2 to 0.3 (released today).
In cucumber, each scenario step in a .feature file matches to a Given, When, Then step definition. The step definitions are normal Ruby code. First class, bonnified, honky-tonk Ruby code. And what’s the one thing we love to do to Ruby code on a rainy Sunday afternoon? Refactor it. In Cucumber we use a special, until-now unknown, magic technique for refactoring step definitions. When /I fill in the Account form/ do fill_in("account_name", :with => "Mocra") fill_in("account_abn", :with => "12 345 678 901") click_button("Submit") end. Imagination is more important than knowledge. [A. Einstein] Dr Nic's Cucumber: building a better World (object) Reference·Cucumber.
This is the general reference for all Cucumber implementations.
Please refer to the documentation overview for links to platform-specific documentation. Cucumber executes your .feature files, and those files contain executable specifications written in a language called Gherkin. Gherkin is plain-text English (or one of 60+ other languages) with a little extra structure. Gherkin is designed to be easy to learn by non-programmers, yet structured enough to allow concise description of examples to illustrate business rules in most real-world domains. Here is a sample Gherkin document: Feature: Refund item Scenario: Jeff returns a faulty microwave Given Jeff has bought a microwave for $100 And he has a receipt When he returns the microwave Then Jeff should be refunded $100 In Gherkin, each line that isn't blank has to start with a Gherkin keyword, followed by any text you like.
FeatureScenarioGiven, When, Then, And, But (Steps)BackgroundScenario OutlineExamples. Predefined Data Types in parse — behave 1.2.5: Examples and Tutorials. What’s in a Story? [This article has been translated into Korean by HongJoo Lee, French by Philippe Poumaroux, Spanish by Adrian Moya, Russian by Denis Oleynik, and German by Julia Kadauke.]
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. This article introduces the BDD approach to defining and identifying stories and their acceptance criteria. Introduction Software delivery is about writing software to achieve business outcomes. Usually, the business outcomes are too coarse-grained to be used to directly write software (where do you start coding when the outcome is “save 5% of my operating costs”?)
This, then, is the role of a Story. Behavior-Driven Development vs. Testing. The difference between Behavior-Driven Development and testing: This is a BDD scenario (from Dan North, a man I respect and admire): +Scenario 1: Account is in credit+ Given the account is in credit And the card is valid And the dispenser contains cash When the customer requests cash Then ensure the account is debited And ensure cash is dispensed And ensure the card is returned This is that BDD scenario turned into testing:
Introducing BDD. History: This article first appeared in Better Software magazine in March 2006.
It has been translated into Japanese by Yukei Wachi, Korean by HongJoo Lee, Italian by Arialdo Martini and French by Philippe Poumaroux and most recently into Spanish by Oscar Zárate, Turkish by Selim Öber and Russian. I had a problem. While using and teaching agile practices like test-driven development (TDD) on projects in different environments, I kept coming across the same confusion and misunderstandings.
Programmers wanted to know where to start, what to test and what not to test, how much to test in one go, what to call their tests, and how to understand why a test fails. The deeper I got into TDD, the more I felt that my own journey had been less of a wax-on, wax-off process of gradual mastery than a series of blind alleys. BDD principles. BDD in Action. Python - Separation of business logic and data access in django. The Truth about BDD - Clean Coder. I really like the concept of BDD (Behavior Driven Development).
I think Dan North is brilliant, and had done us all a great service by presenting the concept. It’s not so much a “but” as an “aha!”. (The punch line is at the end of this article, so don’t give up in the middle.) BDD is a variation on TDD. Whereas in TDD we drive the development of a module by “first” stating the requirements as unit tests, in BDD we drive that development by first stating the requirements as, well, requirements. For example, GIVEN an employee named Bob making $12 per hour. The Given/When/Then convention is central to the notion of BDD. The argued benefit is that the language you use affects the way you think (See this. and so if you use a language closer to the way humans think about problems, you’ll get better thought processes and therefore better results. To say this differently, the Given/When/Then convention stimulates better thought processes than the AssertEquals(expected, actual); convention.
Writing Features — Behat 3.0.12 documentation. Behat is a tool to test the behavior of your application, described in a special language called Gherkin.
Gherkin is a Business Readable, Domain Specific Language created specifically for behavior descriptions. It gives you the ability to remove logic details from behavior tests. Gherkin serves as your project’s documentation as well as your project’s automated tests. Behat also has a bonus feature: It talks back to you using real, human language telling you what code you should write. Tip If you’re still new to Behat, jump into the Building Domain Model first, then return here to learn more about Gherkin.