GivenWhenThen

Trait that contains methods named given, when, then, and and, which take a string message and implicit Informer, and forward the message to the informer.

Here's an example:

package org.scalatest.examples.flatspec.info

import collection.mutable
import org.scalatest._

class SetSpec extends FlatSpec with GivenWhenThen {

 "A mutable Set" should "allow an element to be added" in {
   Given("an empty mutable Set")
   val set = mutable.Set.empty[String]

   When("an element is added")
   set += "clarity"

   Then("the Set should have size 1")
   assert(set.size === 1)

   And("the Set should contain the added element")
   assert(set.contains("clarity"))

   info("That's all folks!")
 }
}

If you run this SetSpec from the interpreter, you will see the following output:

scala> org.scalatest.run(new SetSpec)
A mutable Set
- should allow an element to be added
 + Given an empty mutable Set
 + When an element is added
 + Then the Set should have size 1
 + And the Set should contain the added element
 + That's all folks!