How to create test fixtures for every example of a functional test

Question

Scala noob here.

I currently try to create functional tests for a Play (Scala) based web application using specs2. The examples themselves are simple, i.e.:

class SignInSpec extends PlaySpecification {

  // bring the workflow steps in scope and instrument browser with them    
  import utils.WorkflowSteps.AuthSteps

  "An activated user".should {
    "be able to sign in to the admin console" in new WithDbData(webDriver = WebDriverFactory(FIREFOX)) {

      // this should be: browser.signIn(testData.manager)
      // with the manager already persisted in the database
      browser.signIn(Manager(None, "[email protected]", "12341234", "John", "Doe", List("admin")))
    }
  }
}

What I'd like to achieve is to feed each example with a defined set of test data, some of which will already be persisted in the database. So I need a setup and a teardown method around each example that prepares a TestData case class, fills it with appropriate data and persists some of it so that the example can start with a defined database state. Ultimately I want a plugin mechanism where the plugs defined the test data for a set of examples (think of it as an application of the loan pattern).

What I did so far:

I tried to use some flavour of Around, but I don't know how to feed the data into the example as I'd have to add an additional return value.
I tried specs2's ForEach context, but that conflicts with Play's WithBrowser
I played with implicit vals, but again I don't know how to add an implicit parameter to the block that is transformed from a constructor to a function call parameter using DelayedInit

Any ideas how to proceed to achieve the following ?

Extending the specification or the example from an additional trait or class that calls the example with a single parameter TestData
This additional trait or class should be able to prepare test data and persist parts of it
This additional trait or class should be compatible with WithBrowser

Dima Dima · Accepted Answer · 2019-01-06T14:04:56

One approach is using so called "loan fixtures":

     def withTestData(test: TestData => Unit) = {
       val data = setupTestData() 
       try { 
         test(data)
       } finally {
         destroyTestData(data)
       }
     }



    "An activated user" should "be able to sign in to the admin console" in withTestData { data =>
       new WithDbData(webDriver = WebDriverFactory(FIREFOX)) {
         browser.signIn(data.manager)
       }
     }

etc ..

How to create test fixtures for every example of a functional test

2 Answers