Trait/Object

org.scalatest

OptionValues

Related Docs: object OptionValues | package scalatest

Permalink

trait OptionValues extends AnyRef

Trait that provides an implicit conversion that adds a value method to Option, which will return the value of the option if it is defined, or throw TestFailedException if not.

This construct allows you to express in one statement that an option should be defined and that its value should meet some expectation. Here's an example:

opt.value should be > 9

Or, using an assertion instead of a matcher expression:

assert(opt.value > 9)

Were you to simply invoke get on the Option, if the option wasn't defined, it would throw a NoSuchElementException:

val opt: Option[Int] = None

opt.get should be > 9 // opt.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 OptionValues, to get a stack depth exception you would need to make two statements, like this:

val opt: Option[Int] = None

opt should be ('defined) // throws TestFailedException
opt.get should be > 9

The OptionValues trait allows you to state that more concisely:

val opt: Option[Int] = None

opt.value should be > 9 // opt.value throws TestFailedException

Source
OptionValues.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. OptionValues
  2. AnyRef
  3. Any
  1. Hide All
  2. Show all
Visibility
  1. Public
  2. All

Type Members

  1. class Valuable[T] extends AnyRef

    Permalink

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

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

    opt.value should be > 9
    

Value Members

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

    Permalink
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

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

    Permalink
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0

    Permalink
    Definition Classes
    Any
  5. def clone(): AnyRef

    Permalink
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  6. implicit def convertOptionToValuable[T](opt: Option[T]): Valuable[T]

    Permalink

    Implicit conversion that adds a value method to Option.

    Implicit conversion that adds a value method to Option.

    opt

    the Option on which to add the value method

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

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

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

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

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

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

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

    Permalink
    Definition Classes
    AnyRef
  14. final def notify(): Unit

    Permalink
    Definition Classes
    AnyRef
  15. final def notifyAll(): Unit

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

    Permalink
    Definition Classes
    AnyRef
  17. def toString(): String

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

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

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

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from AnyRef

Inherited from Any

Ungrouped