ScalaMock

Native Scala mocking.

Examples

Mocking objects

def testTurtle {
  val t = mock[Turtle]

  t.expects.penDown()
  t.expects.turn(90.0)
  t.expects.forward(10.0)
  t.expects.getPosition returning (0.0, 10.0)

  drawLine(t)
}

Mocking functions

def testFoldLeft() {
  val f = mockFunction[String, Int, String]

  f expects ("initial", 0) returning "intermediate one"
  f expects ("intermediate one", 1) returning "intermediate two"
  f expects ("intermediate two", 2) returning "intermediate three"
  f expects ("intermediate three", 3) returning "final"

  expect("final") { Seq(0, 1, 2, 3).foldLeft("initial")(f) }
}

Full worked example.

Features

As well as traits (interfaces) and functions, ScalaMock can also mock:

• Classes
• Singleton and companion objects (static methods)
• Object creation (constructor invocation)
• Polymorphic (type parameterised) methods
• Classes with private constructors
• Final classes and classes with final methods
• Operators (methods with symbolic names)
• Overloaded methods

Known limitations:

• No support (yet) for type-parameterised classes.
• No support (yet) for static methods defined in Java.
• No support (yet) for methods that take by-name parameters.
• Methods that take a single tuple argument are broken on 2.9.1 due to a compiler bug.

Downloading

Download from scala-tools.

To use ScalaMock in sbt 0.11 with ScalaTest add the following to your project file:

libraryDependencies +=
  "org.scalamock" %% "scalamock-scalatest-support" % "latest.integration"

Documentation

Scaladoc.

Building

Install sbt 0.11 and then:

sbt generate-mocks
sbt test