Scala Language Spec Test Cheatsheet


Example

Setup

The tests below uses these values for the examples.

val helloWorld = "Hello World"
val helloWorldCount = 1
val helloWorldList = List("Hello World", "Bonjour Le Monde")
def sayHello = throw new IllegalStateException("Hello World Exception")

Type check

To verify the type for a given val:

helloWorld shouldBe a [String]

Note that the brackets here are used to get type String.

Equal check

To test equality:

helloWorld shouldEqual "Hello World"
helloWorld should === ("Hello World")
helloWorldCount shouldEqual 1
helloWorldCount shouldBe 1
helloWorldList shouldEqual List("Hello World", "Bonjour Le Monde")
helloWorldList === List("Hello World", "Bonjour Le Monde")

Not Equal check

To test inequality:

helloWorld should not equal "Hello"
helloWorld !== "Hello"
helloWorldCount should not be 5
helloWorldList should not equal List("Hello World")
helloWorldList !== List("Hello World")
helloWorldList should not be empty

Length check

To verify length and/or size:

helloWorld should have length 11
helloWorldList should have size 2

Exceptions check

To verify the type and message of an exception:

val exception = the [java.lang.IllegalStateException] thrownBy {
  sayHello
}
exception.getClass shouldEqual classOf[java.lang.IllegalStateException]
exception.getMessage should include ("Hello World")