I have a test class that looks like this:

class NetworkEitherCallAdapterTest : StringSpec({

  private lateinit var server: MockWebServer
  private lateinit var service: CallErrorTestClient

  beforeAny {
      server = MockWebServer()
      server.start()
      service = Retrofit.Builder()
      .baseUrl(server.url("/"))
      .addConverterFactory(GsonConverterFactory.create())
      .addCallAdapterFactory(EitherCallAdapterFactory.create())
      .build()
      .create(CallErrorTestClient::class.java)
  }
  afterAny { server.shutdown() }

  "should return ResponseMock for 200 with valid JSON" {
      server.enqueue(MockResponse().setBody("""{"response":"Arrow rocks"}"""))
      val body = service.getEither()
      body shouldBe ResponseMock("Arrow rocks").right()
  }

  // More tests...

I want to run the test class 3 times with different

service

instances (which will use different

ConverterFactory

each). What is the most readable way to achieve it? I don't want to parameterize every test, I want to parameterize the whole class and repeat it.

You could look at test factories.

Thank you for the quick an helpful answer! It looks exactly like what I need ❤️

cool 🙂

How can I make sure though that

server

and

service

are regenerated for each test inside the factory using

beforeAny

?

test factories have beforeTest/beforeAny and it only applies to the tests in that factory

Yes, it's actually logical that I have to make these `var`s nullable, as the test factory is a function and not a class, so I cannot really cheat using

lateinit

as before.

right

It works now with

!!

and I don't mind it.

you could pull the server out

True, thanks!

ah because you change it

I want a new instance of the server in every test so that the server configuration doesn't leak between tests

I guess the server is immutable so you need the var

I want a new server in every test

yep

Because e.g. of such tests:

"should return IOError when no response" {
    server!!.enqueue(MockResponse().apply { socketPolicy = SocketPolicy.NO_RESPONSE })

    val body = service!!.getEither()

    body.shouldBeInstanceOf<Left<IOError>>()
      .value.cause.shouldBeInstanceOf<SocketTimeoutException>()
  }

I guess the alternative would be to have a function that returns a server and call it inside your tests manually.

"mytest" {
  withServer { server- -> 
  }
}

Yes, but that's a bit counterproductive. I rather use the provided test setup/teardown facilities than copy-paste it myself. I can live with a bit of ugliness caused by the

!!

operator.

yeah the power of "tests as functions" really