Specification template

On the Contexts page we saw that there is a way to define an action which will be executed before all examples with the BeforeSpec trait. You actually might want to create your own trait extending BeforeSpec in order to reuse this action in more than one specification:

trait DatabaseSetup extends BeforeSpec:
  def beforeSpec = step(println("prepare database"))

class DatabaseSpecification1 extends Specification with DatabaseSetup:
  def is = s2"""
  // do something with the database
"""

How does this work? The BeforeSpec trait overrides a method called map in the SpecificationStructure trait (a parent of Specification) and adds the fragments defined by beforeSpec before anything else in the specification:

override def map(fs: =>Fragments): Fragments =
  // the AlwaysTag is there to make sure that those fragments are always executed
  // even if we filter by name or other tags
  super.map(fs).prepend(beforeSpec.append(fragmentFactory.markAs(AlwaysTag)))

The map method is indeed called every time the specification returns the list of Fragments defining it. You can leverage this method and define your own “Specification templates”:

• adding some text before/after a Specification
• filtering out some undesirable fragments
• reformatting all text
• …

And if you want to know more