ScalaTest quick start

To get started with ScalaTest, copy this AnyFlatSpec into a file named ExampleSpec.scala:

import collection.mutable.Stack
import org.scalatest._
import flatspec._
import matchers._

class ExampleSpec extends AnyFlatSpec with should.Matchers {

  "A Stack" should "pop values in last-in-first-out order" in {
    val stack = new Stack[Int]
    stack.push(1)
    stack.push(2)
    stack.pop() should be (2)
    stack.pop() should be (1)
  }

  it should "throw NoSuchElementException if an empty stack is popped" in {
    val emptyStack = new Stack[Int]
    a [NoSuchElementException] should be thrownBy {
      emptyStack.pop()
    } 
  }
}

You can compile this FlatSpec (using this Jar file) like this:

$ scalac -cp scalatest-app_3-3.2.19.jar ExampleSpec.scala

To run it, you will need one more artifact, the Jar file for Scala's XML module. Once you've downloaded that Jar file, you can run ExampleSpec like this:

$ CLASSPATH=scalatest-app_3-3.2.19.jar:scala-xml_3-2.3.0.jar
$ scala -cp $CLASSPATH org.scalatest.run ExampleSpec
Run starting. Expected test count is: 2
ExampleSpec:
A Stack
- should pop values in last-in-first-out order
- should throw NoSuchElementException if an empty stack is popped
Run completed in 76 milliseconds.
Total number of tests run: 2
Suites: completed 1, aborted 0
Tests: succeeded 2, failed 0, canceled 0, ignored 0, pending 0
All tests passed.

Your tests passed! As a reward, take a moment to install ScalaTest in your project.