Test-Driven Development and MVP

1
Test-Driven Development and MVP

• Cory Foy and Michael Russo

2
Whats Ahead

• Process
• Flavors
• Techniques
• Demo
• Introducing TDD
• Challenges
• Questions?

3
Process

• Test versus Design
• Red, Green, Refactor
• No Production Code without a Failing Test
• State Based versus Interaction Based Tests

4
Flavors

• Behavior-Driven Development
• Domain-Driven Design
• Acceptance-Test Driven Development
• Feature-Driven Development
• Example-Driven Development
• Hope-Driven Development

5
Techniques - Tools

• xUnit Tools
• .NET NUnit, MbUnit, xUnit.NET, Visual Studio
  Test Tools, TD.NET, Resharper
• Java JUnit, JBehave
• Ruby test_unit, rSpec, Cucumber
• Other Tools
• FitNesse/FIT
• AgileDocs/TestDocs

6
Techniques Rules

• Two main sources of rules
• Feathers Rules from Michael Feathers Working
  Effectively with Legacy Code
• Norths Rules from Dan Norths BDD sessions

7
Techniques Feathers Rules

• Not a unit test if it
• Talks to the database
• Communicates Across the Network
• Touches the File System
• Cant run at the same time as your other unit
  tests
• Have to do special things in your environment to
  run it (config file changes, code changes, etc)

8
Techniques Norths Rules

• Come from Behavior-Driven Development
• Test Method Names should be sentences
• Keep Test Methods Focused
• It should be clear from the name what the test is
  doing
• Behavior is more useful than test
• Acceptance Criteria should be executable
• BDD is an umbiqutious language for analysis

9
Techniques - Spikes

• When it absolutely, positively has to be there
  without tests
• Useful for determining if something is even going
  to work
• Timebox the Spike
• Throw away the code at the end and redo it
  test-first

10
Techniques Helpful Patterns

• Dependency Injection
• Separation of Concerns
• MVP/MVC
• Model View Presenter
• Model View Controller

11
Demo

• TDD / MVC Demo
• Starring
• Michael Russo as Newbie
• Cory Foy as Cory
• The audience as The Hecklers

12
Introducing TDD

• Legacy Code
• Pick up a copy of Working Effectively With Legacy
  Code
• Write unit tests for bugs
• Write Characterization tests for features
• Greenfield Project
• No production code without a failing test
• Executable Specifications
• Automated Acceptance Test Criteria

13
Challenges

• Language Support
• Slow Tests
• Keeping up with the tests
• Developer Mindsets
• Management Mindsets
• Legacy Code

14
Questions?

• Ask now
• Or, you know, ask later, afterwards, or via
  email, or twitter, or well give you our phone
  numbers. Come over for dinner. Well chat more
  then.

15
Information

• Agile Tampa http//agiletampa.spaces.live.com
• Corys Blog http//www.cornetdesign.com
• Agile Florida http//www.agileflorida.com
• NUnit http//www.nunit.org
• FitNesse http//www.fitnesse.org