Scala Test-Driven Development

Matchers

Along with assertion, ScalaTest also supports a domain-specific language (DSL) for expressing assertions in the test. This is achieved using the word should. This is done by mixing in Matchers:

import org.scalatest._  
class PacktSpec extends FlatSpec with Matchers

Alternatively, members of the trait can be imported explicitly:

import Matchers._

ScalaTest has the Matchers trait, which you can mixin to your suite class to write equality assertions like this:

message should equal ("Hello World")

message is a variable and can be of any type. In all the preceding cases, if the equality is not held true, then TestFailedException is thrown. A detail message encapsulated in this exception will explain the problem and why the test failed.

Alternatively, ...