Testing: Python, Java, Groovy, etc.

Testing: Python, Java, Groovy, etc. Prof Russel Winder http://www.russel.org.uk email: russel@winder.org.uk xmpp: russel@winder.org.uk twitter: @russel_winder Copyright 2012 Russel Winder 1

Aims, Goals and Objects Look at some practical aspects of testing with Python, Java, and Groovy. Consider some of the practical positives and negatives of using test-driven development. Possibly look at coverage as a useful tool for programmers. If time permits. And a dangerous weapon in the hands of ignorant managers. Copyright 2012 Russel Winder 2

Structure Introduction. First part. Short break. Second part. Conclusion. Copyright 2012 Russel Winder 3

Protocol Questions or short comments during the sessions are entirely in order. Let me know you have an interjection by raising your hand, and when I come to an appropriate pause, I'll pass you the token. Questions, answers, comments, etc. appearing to get too long as interjections may get stacked to be unstacked at a break. Copyright 2012 Russel Winder 4

Introduction Copyright 2012 Russel Winder 5

Russel Winder Theoretical Physicist: quarks, strangeness, and charm. UNIX systems programmer. Academic at UCL: parallel programming, HCI, psychology of programming. Professor of Computing Science at KCL: health informatics, parallel programming. Head of Department. Starter of start-ups. Independent consultant, analyst, author, expert witness, trainer. Copyright 2012 Russel Winder 6

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Projects Gant GroovyBalls GPars GFontBrowser SCons Pi_Quadrature GroovyFX Sleeping_Barber Groovy Gradle OK, so it's all open source. Copyright 2012 Russel Winder 8

Testing RW Historically The FORTRAN years. The C years. Early Smalltalk and C++ years. The Fortran years. Early Java years. Test-driven Development (TDD) hegemony. Feature-Driven Development (FDD). Behaviour-driven Development (BDD). extreme Programming Copyright 2012 Russel Winder 9

A Personal Epiphany C codes needs testing. C is very difficult re testing. Use Python as long as the C is in a dynamically linked library (aka shared object). Copyright 2012 Russel Winder 10

The Two Parts Copyright 2012 Russel Winder 11

The Terms Unit test. Integration test. System test. Acceptance test. Smoke test. Mutation test. Copyright 2012 Russel Winder 12

Unit Test Test the functions and methods for correct behaviour. May well require use of mocks. Copyright 2012 Russel Winder 13

Integration Test Test that combination of bits of the system collaborate in correct ways. Probably needs some use of mocks. Copyright 2012 Russel Winder 14

System Test Test that the system as a whole works as expected. No mocks at all. Smoke test a pre-test to ensure it is worth running all the tests. Copyright 2012 Russel Winder 15

Acceptance Test Test that the purchaser makes to be happy with the system as delivered. Used to be crucial, now contracts are usually not for one-off items, but for annual support. Copyright 2012 Russel Winder 16

Code under Test Copyright 2012 Russel Winder 17

The Tools Test frameworks: Unit testing Integration testing System testing. Programming language specific. Acceptance testing usually uses a different sort of tool, FitNesse for example. http://fitnesse.org/ Copyright 2012 Russel Winder 18

Testing: A Backdrop Testing as we know it today has its roots in extreme Programming. Smalltalk sunit Python PyUnit (aka unittest) C++ cppunit, Java JUnit Every language created one or many xunit variants on the assumption it was The right thing to do even when it wasn't. Copyright 2012 Russel Winder 19

The xunit Legacy xunit is fundamentally grounded in dynamic languages reflection required. Static languages like C++ need a very different approach, hence CUTE, Catch, using template meta-programming (aka compile time reflection). Static languages like Java, can use annotations still reflection based but better. Copyright 2012 Russel Winder 20

In the Python-sphere PyUnit, aka unittest py.test, aka PyTest Nose, aka nose There are many others but the above are the ones that matter. Copyright 2012 Russel Winder 21

In the JVM-sphere Java: Groovy JUnit3 GroovyTestCase JUnit4 JUnit3 in disguise TestNG Spock Scala Clojure ScalaTest clojure.test ScalaCheck Midje Specs2 lazytest Kotlin, Ceylon, Jython, JRuby, Copyright 2012 Russel Winder 22

Being In Control For all software developments always use a version control system. Given DVCSs such as Git, Mercurial, Bazaar, there are no excuses for not managing development with a version control system. Distributed version control system. Copyright 2012 Russel Winder 23

Individuals / Teams Single developer projects need no other tools. Multi-developer projects need more infrastructure. Copyright 2012 Russel Winder 24

Continuous Integration A process via which all tests are run for all commits to the mainline repository. A continuous integration server monitors the mainline repository. Copyright 2012 Russel Winder 25

Team Workflow Deployment Server Continuous delivery Continuous deployment Developer Developer Mainline Repository System Test Server Developer Developer Developer Continuous Integration Copyright 2012 Russel Winder 26

Buildbot FOSS continuous integration framework written in Python: Single master. Multiple slaves. http://trac.buildbot.net/ http://www.scons.org/ http://buildbot.scons.org/ Copyright 2012 Russel Winder 27

Atlassian Bamboo Commercial continuous integration server, free to FOSS organizations, e.g. Codehaus http://www.codehaus.org/ http://www.atlassian.com/ http://gant.codehaus.org/ Copyright 2012 Russel Winder 28

JetBrains TeamCity Commercial continuous integration server. Free support for FOSS projects. Cloudy. http://www.jetbrains.com/ http://gpars.codehaus.org/ Copyright 2012 Russel Winder 29

The Process Fix CUT Green Red New Test Refactor Copyright 2012 Russel Winder 30

Test-driven Development Never amend your code unless you have a failing test. Unless the change is a refactoring. Run all your tests often. Copyright 2012 Russel Winder 31

Refactoring Ensure there are no pending commits prior to a refactoring. Run all the tests immediately before a refactoring ensure you get a green. Run all the tests immediately after a refactoring ensure you get a green. If a refactoring leads to a red, back out of all the changes. Run the tests and ensure you get a green. Copyright 2012 Russel Winder 32

Unit Testing and Mocks System testing done within a constrained real system not live. Unit and integration testing needs to disconnect from some resources. Copyright 2012 Russel Winder 33

A short Monty Python moment Copyright 2012 Russel Winder 34

Copyright 2012 Russel Winder 35

A Short Coding Dojo Copyright 2012 Russel Winder 36

Conclusion Copyright 2012 Russel Winder 37

Testing It's what programmers do. Copyright 2012 Russel Winder 38

Version Control It's the way programmers work. Copyright 2012 Russel Winder 39

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Testing: Python, Java, Groovy, etc. Prof Russel Winder http://www.russel.org.uk email: russel@winder.org.uk xmpp: russel@winder.org.uk twitter: @russel_winder Copyright 2012 Russel Winder 41