ScalaCheck

The purpose of this lab is to help you become more familiar with ScalaCheck. In particular, we’re going to play around with generators.

You’ll find a lot of useful information in the ScalaCheck User Guide. You may also with to consult the ScalaCheck Documentation for more in-depth information.

Preliminaries

Directory Structure

You should set up a directory that looks like this:

.scalacheck
|-- build.sbt
`-- src
   |-- main
   |   `-- scala
   |       `-- JoinList.scala
   |       `-- Sorting.scala
   `-- test
      `|-- scala
           `-- *your tests go here*

JoinList.scala is available » here «

Sorting.scala is available » here «

build.sbt File

The build.sbt file should have these lines:

scalaVersion := "2.11.2"

resolvers +=
  "Sonatype Releases" at "http://oss.sonatype.org/content/repositories/releases"

libraryDependencies += "org.scalacheck" %% "scalacheck" % "1.11.6" % "test"

libraryDependencies += "org.scalatest" %% "scalatest" % "2.2.1" % "test"

libraryDependencies += "org.scalacheck" %% "scalacheck" % "1.11.6" % "test"

Template File

import org.scalatest._
import org.scalatest.prop._
import Sorting._
import JoinList._
import org.scalacheck._
import Gen._
import Arbitrary.arbitrary

class ScalaCheckTests extends FunSuite with GeneratorDrivenPropertyChecks {
    // Your generators and tests here
    test("This is a sample test, do not keep it.") {
        forAll(someGenerator) {...}
    }
}

Programming Task

Your task is define generators for small integers, lists of small integers, and the JoinList type, in addition to writing tests for all of these generators. All of your code will go in src/test/scala/.

You can run your tests using sbt test as usual.

Hint: The tests for the integer lists can be completed using the List class’s methods.

1. Make a generator called smallIntegers that produces integers between 50 and 150, inclusive.

2. Make a generator called smallIntLists that produces lists of integers between 50 and 100, inclusive.

3. Make a test that checks that all numbers in a list are less than 200.

4. Make a test that counts how many numbers in a list are less than 100. To check the count, filter the list and the check the resulting length.

5. Make a generator for the JoinList[Int] class. You will need to define four generators:

   • Empty
   • Singleton
   • JoinList
   • JoinList[JoinList[Int]]
   • You may use the JoinList.fromList function for the last 2 generators.

6. Reimplement the tests from class, but use the JoinList generators that you defined above instead.

Submit Your Work

Upload only the test file to Moodle.

If you work with a partner: Both of you should submit the file. In addition, put a comment with both of your names at the top of the file.

For example, at the top of ScalaCheckLabTests.scala:

// Completed by: Sarah Scalington and Jack Javahead