OptionValues
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
Implicit conversion that adds a value method to Option.
Implicit conversion that adds a value method to Option.
the Option on which to add the value method
Trait that provides an implicit conversion that adds a
valuemethod toOption, which will return the value of the option if it is defined, or throwTestFailedExceptionif 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:
Or, using an assertion instead of a matcher expression:
Were you to simply invoke
geton theOption, if the option wasn't defined, it would throw aNoSuchElementException:The
NoSuchElementExceptionwould cause the test to fail, but without providing a stack depth pointing to the failing line of test code. This stack depth, provided byTestFailedException(and a few other ScalaTest exceptions), makes it quicker for users to navigate to the cause of the failure. WithoutOptionValues, 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 > 9The
OptionValuestrait allows you to state that more concisely: