EitherValues

Trait that provides an implicit conversion that adds value (when you expect a Right) and left.value (when you expect a Left) 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.value should be > 9
either2.left.value should be ("Muchos problemas")

Or, using assertions instead of matcher expressions:

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

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

val either: Either[String, Int] = Right(9)

either.left.get should be > "Muchos problemas" // 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] = Right(9)

either should be ('left) // throws TestFailedException
either.left.get should be > "Muchos problemas"

The EitherValues trait allows you to state that more concisely:

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

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

Source: EitherValues.scala

Linear Supertypes

Serializable, Serializable, AnyRef, Any

Known Subclasses

EitherValues

Type Members

class LeftValuable[L, R] extends Serializable

Wrapper class that adds a value method to LeftProjection, allowing you to make statements like:
class RightValuable[L, R] extends Serializable

Wrapper class that adds a value method to RightProjection, allowing you to make statements like:
class Valuable[L, R] extends Serializable

Wrapper class that adds a value method to Either, allowing you to make statements to inspect the value if a Right, like:

Value Members

final def !=(arg0: AnyRef): Boolean

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

Definition Classes
Any
final def ##(): Int

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

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

Definition Classes
Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
implicit def convertEitherToValuable[L, R](either: Either[L, R])(implicit pos: Position): Valuable[L, R]

Implicit conversion that adds a value method to Either.
Implicit conversion that adds a value method to Either. This method is right biased and is the equivalent of calling either.right.value.
either
the Either on which to add the value method
implicit def convertLeftProjectionToValuable[L, R](leftProj: LeftProjection[L, R])(implicit pos: Position): LeftValuable[L, R]

Implicit conversion that adds a value method to LeftProjection.
Implicit conversion that adds a value method to LeftProjection.
leftProj
the LeftProjection on which to add the value method
final def eq(arg0: AnyRef): Boolean

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

Definition Classes
AnyRef → Any
def finalize(): Unit

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

Definition Classes
AnyRef → Any
def hashCode(): Int

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

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

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

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

Definition Classes
AnyRef
def toString(): String

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

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

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

Definition Classes
AnyRef
Annotations
@throws( ... )

Deprecated Value Members

implicit def convertRightProjectionToValuable[L, R](rightProj: RightProjection[L, R])(implicit pos: Position): RightValuable[L, R]

Implicit conversion that adds a value method to RightProjection.
Implicit conversion that adds a value method to RightProjection.
rightProj
the RightProjection on which to add the value method

Annotations
@deprecated
Deprecated
The .right.value syntax on Either has been deprecated and will be removed in a future version of ScalaTest. Please use .value instead.

trait EitherValues extends Serializable

Type Members

class LeftValuable[L, R] extends Serializable

class RightValuable[L, R] extends Serializable

class Valuable[L, R] extends Serializable

Value Members

final def !=(arg0: AnyRef): Boolean

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: AnyRef): Boolean

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def clone(): AnyRef

implicit def convertEitherToValuable[L, R](either: Either[L, R])(implicit pos: Position): Valuable[L, R]

implicit def convertLeftProjectionToValuable[L, R](leftProj: LeftProjection[L, R])(implicit pos: Position): LeftValuable[L, R]

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Deprecated Value Members

implicit def convertRightProjectionToValuable[L, R](rightProj: RightProjection[L, R])(implicit pos: Position): RightValuable[L, R]

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped