Behavior Driven Development Using Visual Studio 2010 And SpecFlow

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Behavior Driven DevelopmentUsing Visual Studio 2010 AndSpecFlow

Ivan Pavlović, Hive StudiosVisual C# MVP, MCT, [email protected] http://msforge.net/blogs/pakihttp://twitter.com/ipavlovi

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AgendaLittle bit of slides, a lot of examples

What is BDDLanguageToolsDemos

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Types of TestUnit testingAcceptance / Customer testingIntegration testingPerformance testingRegression testing

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Behaviour Driven DevelopmentOne of agile development techniques

Specification driven by examplesClear communication between domain experts, developers, testers and customers

BDD is a second-generation, outside-in, pull-based, multiple-stakeholder, multiple-scale, high-automation, agile methodology. It describes a cycle of interactions with well-defined outputs, resulting in the delivery of working, tested software that matters. - Dan North (http://dannorth.net/)

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GherkinDomain Specific LanguageEasy to understand by customersSimple sintax, few keywords

FeatureBackgroundScenario, Scenario OutlineGiven, When, Then

Localized on 35+ languages

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Example 1: Feature: Some descriptive text of what is desired 2: In order to realize a named business value 3: As an explicit system actor 4: I want to gain some beneficial outcome which furthers the goal 5: 6: Scenario: Some determinable business situation 7: Given some precondition 8: And some other precondition 9: When some action by the actor10: And some other action11: And yet another action12: Then some testable outcome is achieved13: And something else we can check happens too14: 15: Scenario: A different situation16: ...

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Real exampleFeature: Serve coffee In order to earn money Customers should be able to buy coffee at all times

Scenario: Buy last coffee Given there are 1 coffees left in the machine And I have deposited 1$ When I press the coffee button Then I should be served a coffee

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ToolsTools are generating *.feature files

Cucumber – Ruby, http://cukes.info/

SpecFlow – .NET, http://specflow.orgNunit, MSTest, MBUnit…

…a lot of other tools

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Putting All The Pieces Together1. User writes features & scenarios, clarify2. SpecFlow generates one test per scenario3. Developer runs test4. Developer implements missing steps5. Developer writes production code6. Move to the next scenario

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Mapping Step Definitions… 7: Given some precondition 8: And some other precondition 9: When some action by the actor10: Then some testable outcome is achieved

[Given(@„some precondition")]public void SomePrecondition() { … do something… }

[Given(@„some other precondition")]public void SomePrecondition() { … do something… }

[When(@„some action by the actor")]public void SomePrecondition() { … do something… }

[Then(@”some verifiable result”)]Public void VerifyResult() { … do assert… }

TEST RUN

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Step Arguments - RegEx… 7: Given I have 5 apples 8: And I eat 2 of them 9: When someone asks how many apples I do have 10: Then I should answer “3 apples”[Given(@„I have (.*) apples")]public void SomePrecondition(int numberOfApples) { … do something… }

[Given(@„ I eat (.*) of them")]public void SomePrecondition(int numberOfEatenApples) { … do something… }

[When(@„ someone asks how many apples I do have")]public void SomePrecondition() { … do something… }

[Then(@” I should answer \“(.*) apples\””)]Public void VerifyResult(int expected) { … do assert of expected … }

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Scenario: Posting a valid entry Given I am on the posting page And I have filled out the form as follows | Label | Value | | Your name | Jakob | | Your comment | Das ist gut! | When I click the button labelled "Post" Then I should be on the guestbook page And the guestbook entries includes the following | Name | Comment | Posted date | | Jakob | Das ist gut! | (within last minute) |

Table Parameters

[Given(@"I have filled out the form as follows")]public void FillFormAsFollows(TechTalk.SpecFlow.Table table) { foreach (var row in table.Rows) { ….. Do something … }}

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Scenario outline - refactoringScenario: TC1 Add two numbersGiven I have entered 1 into the calculatorAnd I have entered 2 into the calculatorWhen I press addThen the result should be 3 on the screen

Scenario: TC2 Add two numbersGiven I have entered 2 into the calculatorAnd I have entered 2 into the calculatorWhen I press addThen the result should be 4 on the screen

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Scenario outline - refactoringScenario Outline: TC5Given I have entered <x> into the calculatorAnd I have entered <y> into the calculatorWhen I press addThen the result should be <result> on the screen

Scenarios: addition| x | y | result|| 1 | 2 | 3 || 2 | 2 | 4 || 3 | -3 | 0 |

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How to Implement Step Definitions?

It’s up to you!What you are testing?

1. Public Interfaces / Components2. WebUI using browser automation

• WatiN, Selenium3. WebUI using Request/Respons

• Http Get/Post4. Win UI using automation

• White / Windows UI Automation

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Resources• Specflow

• http://specflow.org

• Gherkin• https://

github.com/aslakhellesoy/cucumber/wiki/gherkin

• White• http://white.codeplex.com/

• WatiN• http://watiN.sourceforge.net