org.scalatest

EitherValues

trait EitherValues extends AnyRef

Trait that provides an implicit conversion that adds left.value and right.value methods to Either, which will return the selected value of the Either if defined, or throw TestFailedException if not.

This construct allows you to express in one statement that an Either should be left or right and that its value should meet some expectation. Here's are some examples:

either1.right.value should be > 9
either2.left.value should be ("Muchas problemas")

Or, using assertions instead of matcher expressions:

assert(either1.right.value > 9)
assert(either2.left.value === "Muchas problemas")

Were you to simply invoke right.get or left.get on the Either, if the Either wasn't defined as expected (e.g., it was a Left when you expected a Right), it would throw a NoSuchElementException:

val either: Either[String, Int] = Left("Muchas problemas")

either.right.get should be > 9 // either.right.get throws NoSuchElementException

The NoSuchElementException would cause the test to fail, but without providing a stack depth pointing to the failing line of test code. This stack depth, provided by TestFailedException (and a few other ScalaTest exceptions), makes it quicker for users to navigate to the cause of the failure. Without EitherValues, to get a stack depth exception you would need to make two statements, like this:

val either: Either[String, Int] = Left("Muchas problemas")

either should be ('right) // throws TestFailedException either.right.get should be > 9

The EitherValues trait allows you to state that more concisely:

val either: Either[String, Int] = Left("Muchas problemas")

either.right.value should be > 9 // either.right.value throws TestFailedException

Source
EitherValues.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. EitherValues
  2. AnyRef
  3. Any
  1. Hide All
  2. Show all
Learn more about member selection
Visibility
  1. Public
  2. All

Type Members

  1. class LeftValuable[L, R] extends AnyRef

    Wrapper class that adds a value method to LeftProjection, allowing you to make statements like:

  2. class RightValuable[L, R] extends AnyRef

    Wrapper class that adds a value method to RightProjection, allowing you to make statements like:

Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any
  3. final def ##(): Int

    Definition Classes
    AnyRef → Any
  4. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  5. final def ==(arg0: Any): Boolean

    Definition Classes
    Any
  6. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  7. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  8. implicit def convertLeftProjectionToValuable[L, R](leftProj: LeftProjection[L, R]): LeftValuable[L, R]

    Implicit conversion that adds a value method to LeftProjection.

  9. implicit def convertRightProjectionToValuable[L, R](rightProj: RightProjection[L, R]): RightValuable[L, R]

    Implicit conversion that adds a value method to RightProjection.

  10. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  11. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  12. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  13. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any
  14. def hashCode(): Int

    Definition Classes
    AnyRef → Any
  15. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any
  16. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  17. final def notify(): Unit

    Definition Classes
    AnyRef
  18. final def notifyAll(): Unit

    Definition Classes
    AnyRef
  19. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  20. def toString(): String

    Definition Classes
    AnyRef → Any
  21. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws()
  22. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws()
  23. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws()

Inherited from AnyRef

Inherited from Any

Ungrouped