Test Driven Development

Examples of OSS projects that use TDD

Best examples

• http://junit.org/
  • Well-known java unit testing framework written by Kent Beck, inventor or TDD himself
  • https://github.com/junit-team/junit
  • https://github.com/junit-team/junit/tree/master/src/test
  • ex of actual test code: https://github.com/junit-team/junit/blob/master/src/test/java/junit/tests/framework/AssertTest.java

• https://github.com/unclebob/fitnesse
  • Written by one of the Agile Manifesto co-authors
  • Very clean code, tests in /test directory
  • Not as well known, but might be easier for students to understand

Weaker examples

• https://github.com/rails/rails
  • It is said that much of anything rails is developed via TDD
  • https://travis-ci.org/rails/rails
  • https://github.com/rails/rails/pull/23690

• http://www.sqlite.org/testing.html
  • Superb write up by SQLite of how they do extensive testing, but its possibly not developed with TDD principles, or maybe partially.

• https://github.com/AutoFixture/AutoFixture
  • Another TDD example project, but its around .NET .... meh
  • https://github.com/AutoFixture/AutoFixture/blob/master/Src/AutoFixture.xUnit.net.UnitTest/AutoDataAttributeTest.cs

TDD "Lessons"

• http://www.codeaffine.com/2014/08/12/junit-in-a-nutshell-hello-world/ , http://www.codeaffine.com/2012/11/26/working-efficiently-with-junit-in-eclipse-2/
  • A superbly written step-by-step walk through of creating a test and then creating the associated functional code
  • It uses JUnit, which is an open source technology - but it uses a helloworld example - not sure if we want this or more of an integration with an existing oss project
  • Code Affine gave us permission to use!

• https://schuchert.wikispaces.com/Cxx+TDD+Monopoly
  • Line-by-line explanation of code and tests and process to create Monopoly features via TDD
  • Not sure what students would do, as all answers are given
  • CC-BY-SA

• https://dzone.com/articles/Write-JUnit-Tests-in-Spring-With-Mocked-and-Real-Objects
  • Specific to spring framework, and not for beginners; possibly complex to implement for beginners
  • I think DZone is copyright encumbered :-/ all content on it is proprietary in their submission legal text

• http://technologyconversations.com/2013/12/20/test-driven-development-tdd-example-walkthrough/ http://osherove.com/tdd-kata-1/ https://vimeo.com/8506325
  • These are a great series of TDD "Practice Exercises"; It gives you requirements that you are supposed to serially step through and implement on top of each other
  • This uses open source, but it isn't involved in any existing oss project
  • Unknown copyright

• https://github.com/orfjackal/tdd-tetris-tutorial
  • Tetris based TDD
  • It gives you test cases, already written, and you code to satisfy the tests
  • License says "You may use and modify this material freely for personal non-commercial use. This material may NOT be used as course material without prior written agreement."

Background reading

• 5 min TDD overview https://www.youtube.com/watch?v=QCif_-r8eK4
• Graphical explanation of TDD http://www.agiledata.org/essays/tdd.html
• Is TDD Dead? https://www.youtube.com/watch?v=z9quxZsLcfo
• Kent Beck book http://www.amazon.com/exec/obidos/ASIN/0321146530/
• Astels book http://www.amazon.com/exec/obidos/ASIN/0131016490/
• Unit test vs Acceptance test https://dzone.com/articles/Write-JUnit-Tests-in-Spring-With-Mocked-and-Real-Objects
• TDD in a CalPoly course https://users.csc.calpoly.edu/~djanzen/courses/405W10/presentations/TDD.pdf
• Research showing TDD's pro's and con's https://tuhat.halvi.helsinki.fi/portal/files/29553974/2014_01_swqd_author_version.pdf
• Lists all open source testing tools - http://www.opensourcetesting.org/

Ideas and research

TDD

• Idea 1: Find a project that already has a testing harness and associated tests; learn it, and add a new unit test
• Idea 2: Create a test harness to make, build, and run unit tests on an existing open source project
  • Jim Bowring has done this in the past, though it seems they are lengthy projects vs a shorter activity; Do we want to create a “project”-oriented LA?
• Idea 3: Use an existing JUnit exercise / tutorial to teach a simple TDD 'test first, code later' scenario

• Teach the “mental discipline” of testing
• How can we test a Requirement?
  • Ensuring testing starts at user requirement gathering
  • Iterating through tests once code has been written, helps to improve the tests

• Dave thinks ManageIQ does unit testing

• Background reading:
  • http://www.cs.cofc.edu/~bowring/ - course in testing
  • Boris Byser - the test guru
  • Kent Beck - extreme programming (ford motor)
  • http://foss2serve.org/index.php/Test_Coverage_Activity