scalatestMatchersCoreDotty/org.scalatest.matchers/MatcherProducers

MatcherProducers

object MatcherProducers extends MatcherProducers

Companion object that facilitates the importing of MatcherProducers members as an alternative to mixing it in. One use case is to import MatcherProducers's members so you can use MatcherProducers in the Scala interpreter.

Companion:
class
class Object
trait Matchable
class Any

Type members

Inherited classlikes

class Composifier[T](f: T => Matcher[T])

Class used via an implicit conversion that adds composeTwice, mapResult, and mapArgs methods to functions that produce a Matcher.

Class used via an implicit conversion that adds composeTwice, mapResult, and mapArgs methods to functions that produce a Matcher.

Inherited from:
MatcherProducers

Implicits

Inherited implicits

implicit def convertToComposifier[T](f: T => Matcher[T]): Composifier[T]

Implicit conversion that converts a function of T => Matcher[T] to an object that has composeTwice, mapResult and mapArgs methods.

Implicit conversion that converts a function of T => Matcher[T] to an object that has composeTwice, mapResult and mapArgs methods.

The following shows how this trait is used to compose twice and modify error messages:

import org.scalatest._
import matchers._
import MatcherProducers._

val f = be > (_: Int)
val g = (_: String).toInt

// f composeTwice g means: (f compose g) andThen (_ compose g)
val beAsIntsGreaterThan =
 f composeTwice g mapResult { mr =>
   mr.copy(
     failureMessageArgs =
       mr.failureMessageArgs.map((LazyArg(_) { "\"" + _.toString + "\".toInt"})),
     negatedFailureMessageArgs =
       mr.negatedFailureMessageArgs.map((LazyArg(_) { "\"" + _.toString + "\".toInt"})),
     midSentenceFailureMessageArgs =
       mr.midSentenceFailureMessageArgs.map((LazyArg(_) { "\"" + _.toString + "\".toInt"})),
     midSentenceNegatedFailureMessageArgs =
       mr.midSentenceNegatedFailureMessageArgs.map((LazyArg(_) { "\"" + _.toString + "\".toInt"}))
   )
 }

"7" should beAsIntsGreaterThan ("8")

The last assertion will fail with message like this:

"7".toInt was not greater than "8".toInt
Type parameters:
T

the type used by function f

Value parameters:
f

a function that takes a T and return a Matcher[T]

Returns:

an object that has composeTwice, mapResult and mapArgs methods.

Inherited from:
MatcherProducers