Specs2 - Mock objects inside method - scala

Question

I'm writting unit tests and i would like to know if it's possible to mock an object that is instanced inside the method that i'm testing.
Here is an example of a method that i would like to test:
def sendMessageToBroker(message:Message) = {
val soapBody = xmlBody("user", "pass", message.identifier,
message.to, message.message)
val response = new WebServiceUtil().doPost("uri", soapBody.toString(),
"text/xml; charset=utf-8", "action")
response
}
I was wondering if it's possible to do something like:
when call doPost, return new Response(200, 'Success')
Is it possible?
I've tried do it using spy() and mock, but no sucess:
val ws = new WebServiceUtil
val spiedObj = spy(ws)
spiedObj.doPost("uri", xml,
"text/xml; charset=utf-8",
"action") returns new Response(200, "Success")
val xx = messageService.sendMessageToBroker(new Message())
Any ideas on how can i do it?

Answer 1

You could write
val webService = mock[WebServiceUtil]
webService.doPost("uri", xml, "text/xml; charset=utf-8", "action") returns
new Response(200, "Success")
// pass the mock webservice as an argument
sendMessageToBroker(new Message, webService)
The important part is that you need to be able to pass a mock WebServiceUtil to your method being tested! There are many ways to do that. The simplest one is to pass the instance to a constructor method of our "class under test":
class MyClass(webService: WebServiceUtil) {
def sendMessageToBroker(message: Message) = {
// use the webservice
}
}
A more involved method would use Guice and the Inject annotation to pass the service (especially since you tagged the question as a play-framework-2.0 one). You will be interested in following this SOF question then.