ScalaMock

Native Scala mocking.

For the current status of ScalaMock, see this blog post.

This is ScalaMock 3, which supports Scala 2.10 only. For earlier versions of Scala, see ScalaMock 2.

Examples

Expectations-First Style

def testTurtle {
  val m = mock[Turtle]                              // Create mock Turtle object

  (m.setPosition _).expects(10.0, 10.0)             //
  (m.forward _).expects(5.0)                        // Set expectations
  (m.getPosition _).expects().returning(15.0, 10.0) // 

  drawLine(m, (10.0, 10.0), (15.0, 10.0))           // Exercise System Under Test
}

Record-then-Verify (Mockito) Style

def testTurtle {
  val m = stub[Turtle]                              // Create stub Turtle
  
  (m.getPosition _).when().returns(15.0, 10.0)      // Setup return values

  drawLine(m, (10.0, 10.0), (15.0, 10.0))           // Exercise System Under Test

  (m.setPosition _).verify(10.0, 10.0)              // Verify expectations met
  (m.forward _).verify(5.0)                         //
}

Full worked example

Features

• Fully typesafe
• Full support for Scala features such as:
  • Polymorphic (type parameterised) methods
  • Operators (methods with symbolic names)
  • Overloaded methods
  • Type constraints
• ScalaTest and Specs2 integration

Downloading

Download from Sonatype.

To use ScalaMock in sbt with ScalaTest add the following to your project file:

libraryDependencies +=
  "org.scalamock" %% "scalamock-scalatest-support" % "3.0.1" % "test"

and with Specs2:

libraryDependencies +=
  "org.scalamock" %% "scalamock-specs2-support" % "3.0.1" % "test"

Documentation

Scaladoc.

Future Plans

When Scala supports macro types, this will enable:

• Improved syntax:

  mockObject.expects.method(arguments)
  

  instead of:

  (mockObject.method _) expects (arguments)
  

• Mocking object creation (constructors)

• Mocking singleton and companion objects (static methods)

• Mocking final classes and classes with final methods or private constructors

Acknowledgements

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