NUnit A Pragmatic Approach

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NUnit A Pragmatic Approach

• by Paul Lockwood (dotnetchap_at_hotmail.com)
• BCP Warning
• Please ask questions AT ANY TIME

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Presentation Summary

• What is NUnit
• Pros Cons
• History of TDD
• Demonstration
• Advanced Techniques

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What is NUnit?

• Facilitates Automated Unit Testing
• Unit testing is code driven
• Part of Daily Build and Smoke
• Checking-in code is less risky
• What the Heck is he talking about?
• Quick Demo

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Pros and Cons

• The Good
• Regression Errors spotted Early
• Much more testing will happen
• Takes minutes to test if you support a new
  Service Pack, Database, OS etc
• The Bad
• Extra Work (20-50) Can double development time
• Rework of tests if requirements change
• The Ugly
• Management buy in
• Developer buy in

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History of xUnit

• Smalltalk Test Harnesses
• Smalltalk yet again!
• JUnit
• Kent Becks work
• Refactoring
• MEME reaching the masses now
• Can Refactor Mercilessly with xUnit
• XP and Agile Development
• Test Driven Development (TDD)
• Starts becoming High Church
• Scares many managers

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Wake Up VS.Net time

• Imprecise Date Demo
• Break the code
• How long that normally have taken to find?

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NUnit v1 -gtv2.x

• Now uses Attributes
• 'The new version is NUnit as it would have been
  done had it been done in C to begin with Kent
  Beck
• Adding a new Test Class
• TestFixture
• Test
• Doing the tests
• Assert.Equal(..)
• Assert.Same(..)
• Assert.IsTrue(..)

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More NUnit Attributes

• Often need to set up data
• TestFixtureSetUp
• TestFixtureTearDown
• Look at Pauls current project
• Ignore (Refactoring until 7/18/04")
• Looks useful for large projects
• Category("LongRunning")
• Here in v2.2

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The Bad and Ugly revisited

• Buy in no one likes extra work
• Psychology create a buzz, senior developers
  first
• Clover.Net can Police compliance
• Moving to new OS, SP etc helps sell
• How much extra work?
• White-box vs Black-box testing
• Personally I mostly only test public APIs

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Advanced Techniques 1

• Enterprise Level Testing
• e.g. A Database is required for tests
• Create tables/ data in Setup
• Destroy table/ data in TearDown
• Need to persist across a tests?
• Creating a database is slow
• Singleton Dispose and timer thread works great
  (mail me)
• Use by all developers is challenging

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Advanced Techniques 2

• MVC Design Pattern
• Code can act more like a user
• Tests everything but presentation layer
• May need Mock Objects
• Debugging with NUnit
• Very Simple, Tools-gtDebug Process
• Anyone wish to see this?

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Final Tips

• Include nunit.framework.dll in project
• Make life easier for developers
• Destroy all Singletons - (IDisposable)
• And any other state!!
• Testing stateless classes is easiest
• nunit.org/attributes.html
• Simple to follow
• VS 2005 Team System (WhiteHorse)
• Migrating NUnit tests is easy

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Questions Last chance to Heckle

• Slides are ltTBDgt
• Marc Cliftons Code Project Articles
• DotNetRocks.com
• msdn.microsoft.com/dotnetrocks/
• June 17 67