https://github.com/deanwampler/scalatest_scalacheck_deepdive

Code for the Chicago-Area Scala Enthusiasts Meeting, 12/17/209
https://github.com/deanwampler/scalatest_scalacheck_deepdive

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Code for the Chicago-Area Scala Enthusiasts Meeting, 12/17/209

• Host: GitHub
• URL: https://github.com/deanwampler/scalatest_scalacheck_deepdive
• Owner: deanwampler
• Created: 2009-12-17T04:15:27.000Z (about 15 years ago)
• Default Branch: master
• Last Pushed: 2009-12-19T02:07:01.000Z (about 15 years ago)
• Last Synced: 2024-10-12T15:10:57.178Z (2 months ago)
• Language: Scala
• Homepage: http://polyglotprogramming.com
• Size: 836 KB
• Stars: 5
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.html

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README

        


  ScalaTest and ScalaCheck Deep Dive

  
ScalaTest and ScalaCheck Deep Dive


  
Chicago-Area Scala Enthusiasts

  December 17, 2009


  
Introduction


  
This meeting is a deeper dive into ScalaTest, covering the major “style” options available. Then we’ll talk about ScalaCheck, a port of Haskell’s QuickCheck, which approaches testing from a functional perspective.


  
In ScalaCheck, you specify the properties for a type and verify that those properties are satisfied using an automatically-generated and representative sample of instances of the type. It’s a very different style than XUnit or BDD style testing that you might already know.


  
We’ll work through examples of all these approaches using a simple Complex number class. Then you can play with the test styles using a provided Rational number class. (There isn’t a presentation to go with this code…)


  
Getting the Code


  
git clone git://github.com/deanwampler/ScalaTest_ScalaCheck_DeepDive.git

  


  
Here is the GitHub project web site.


  
Building and Testing


  
The code uses sbt, the Simple Build Tool. The jar for it is in the lib directory and two driver scripts are provided in the bin directory.


  
bin/sbt       # Mac OS, Linux, or Unix (maybe Cygwin?)

  bin\sbt.bat   # Windows

  


  
The code works with Scala 2.7.7 (which the SBT build will install). The code may work with earlier versions of Scala and possibly with Scala 2.8.0. You can experiment with different versions by changing the value for the scala.version property in project/build.properties. See also the additional dependencies that are defined in project/build/ScalaTestingDeepDive.scala.


  
Also, if you want to are 2.8, please check the SBT website to find out if you need a different sbt-launcher-X.Y.Z.jar version. If so, replace the one in the lib directory.


  
Starting SBT


  
To begin, run either bin/sbt or bin\sbt.bat.


  
At the prompt Run the following commands.


  
> help

  > update

  > test

  


  
The help action isn’t really required, but now you know what to do when you have questions…


  
The update action pulls down the other dependencies (required). 


  
The test action will first compile all the files, then run the tests. The (lengthy) output should end with the following:


  
[info] ...

  [info] == test-finish ==

  [info] Run: 24, Passed: 24, Errors: 0, Failed: 0

  [info]  

  [info] All tests PASSED.

  [info] == test-finish ==

  [info] 

  [info] == test-cleanup ==

  [info] == test-cleanup ==

  [info] 

  [info] == test ==

  [info] == test ==

  [success] Successful.

  [info] 

  [info] Total time: 6 s

  >

  


  
SBT has the cool feature that you can define an action to run after every change to the file system. This saves you the trouble of manually invoking a target, like test each time.


  
> ~ test

  


  
I recommend you do this for the rest of the session. (You can hit <return> to break out of it at any time.)


  
Learning about ScalaTest and ScalaCheck


  
We’ll walk through all the examples using different syntax options for ScalaTest and the different approach of ScalaCheck, both using a simple Complex number class. Feel free to use any editor to view the files. 


  
The file complex.scala is in src/main/scala. (You’ll also find rational.scala, which we’ll discuss shortly.)


  
The corresponding ScalaTest files are src/test/scala/complex-*-test.scala. The ScalaCheck file is src/test/scala/complex-check.scala. 


  
Your Exercise, Should You Choose to Accept It


  
The rational.scala file defines a Rational class with a little more detail than the Complex class. Pick one or more of the ScalaTest styles and create tests that exercise the Rational class. Do the same thing for ScalaCheck testing.


  
See the ScalaTest and ScalaCheck documentation for more detailed examples, “scaladocs”, etc.