Index: core-module/pom.xml
===================================================================
diff -u -rc41ae0ad9e7fe3b7781abd7686d5a1cbf2a4be3c -re3041de1aa7ca084d9be5b77ec03656b930fed71
--- core-module/pom.xml	(.../pom.xml)	(revision c41ae0ad9e7fe3b7781abd7686d5a1cbf2a4be3c)
+++ core-module/pom.xml	(.../pom.xml)	(revision e3041de1aa7ca084d9be5b77ec03656b930fed71)
@@ -46,6 +46,12 @@
             <artifactId>scala-library</artifactId>
             <version>2.12.6</version>
         </dependency>
+        <dependency>
+            <groupId>org.scalatest</groupId>
+            <artifactId>scalatest</artifactId>
+            <version>1.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
Index: core-module/src/test/scala/tutorial/Pizza.scala
===================================================================
diff -u
--- core-module/src/test/scala/tutorial/Pizza.scala	(revision 0)
+++ core-module/src/test/scala/tutorial/Pizza.scala	(revision e3041de1aa7ca084d9be5b77ec03656b930fed71)
@@ -0,0 +1,15 @@
+package tutorial
+
+import scala.collection.mutable.ArrayBuffer
+
+case class Topping(name: String)
+
+class Pizza {
+
+  private var toppings = new ArrayBuffer[Topping]
+
+  def addTopping (t: Topping) { toppings += t}
+  def removeTopping (t: Topping) { toppings -= t}
+  def getToppings = toppings.toList
+
+}
\ No newline at end of file
Index: core-module/src/test/scala/tutorial/PizzaTests.scala
===================================================================
diff -u
--- core-module/src/test/scala/tutorial/PizzaTests.scala	(revision 0)
+++ core-module/src/test/scala/tutorial/PizzaTests.scala	(revision e3041de1aa7ca084d9be5b77ec03656b930fed71)
@@ -0,0 +1,26 @@
+package tutorial
+
+import org.junit.Test
+import junit.framework.TestCase
+import org.junit.Assert._
+
+class PizzaTests extends TestCase {
+
+  var pizza: Pizza = _
+
+  override def setUp {
+    pizza = new Pizza
+  }
+
+  def testOneTopping {
+    pizza.addTopping(Topping("green olives"))
+    assertEquals(pizza.getToppings.size, 1)
+  }
+
+  def testAddingAndRemovingToppings {
+    pizza.addTopping(Topping("green olives"))
+    pizza.removeTopping(Topping("green olives"))
+    assertEquals(pizza.getToppings.size, 0)
+  }
+
+}
\ No newline at end of file