Use ApolloTestSupport with Fragment

[Karram-Ayman]

Question

Hey Team,

I’ve integrated ApolloTestSupport v1.24.0, and as expected, we can use Mock<ApolloAPI.Object>.
However, I couldn’t find a way to use Mock<SelectionSet, Fragment>, even though our project relies heavily on fragments.

I’m wondering — is there a way to mock a fragment directly, for example using Mock?

Thanks!

[calvincestari]

Hi @Karram-Ayman, the documentation "Creating response models from test mocks" is the section that you're looking for.

The easiest way to think about it is that Mock<ApolloAPI.Object> lets you mock a schema type. Once you have that schema type mock object you then convert that into a RootSelectionSet conforming model, and all generated operation and fragment models conform. Below is a slightly longer example that illustrates what I mean.

Given these schema types:

type Query {
  hero: Hero!
}

type Hero {
  id: ID!
  name: String!
  friends: [Hero]
}

..and this operation:

query Heros {
  hero {
    ...HeroBaseFragment
    friends {
      ...HeroBaseFragment
    }
  }
}

fragment HeroBaseFragment on Hero {
  id
  name
}

Once codegen has generated the models you can then build your mocks like this:

let darthMaul = Mock<Hero>(
  id: "2",
  name: "Darth Maul"
)

let grevious = Mock<Hero>(
  friends: [
    darthMaul
  ],
  id: "1",
  name: "Grevious"
)

let herosQuery = await GraphAPI.HerosQuery.Data.Hero.from(grevious)
let heroBaseFragment = await GraphAPI.HeroBaseFragment.from(darthMaul)

Hope that helps get you unstuck.

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[Karram-Ayman]

Thanks @calvincestari