How to implement data fetchers for nested mutation types

[sriramgopalan-awx]

type Mutation {
    topLevel: MyTopLevelMutation!
}

type MyTopLevelMutation {
 
    signUp(input: UserInput!): UserPayload!
    
    #...more mutations
}

type UserInput {
   first: String!
   last: String!
}

type UserPayload {
    success: Boolean!
    id: ID!
}

As you see in the above schema, I have a nested mutation structure and the operations are not at the root level. Now how do I implement data fetchers for topLevel which is of type mutation and for signUp field which is of type MyTopLevelMutation ? Any help will be really appreciated.

#528 - In this issue they refer to testing but I would like to know the implementation of the data fetchers.

[justincohan]

I had to do something like this example where I have a mutation that returns a class with a reference to the nested payload which will be populated by the function annotated with @DgsData

@DgsComponent
class MyResolver() {

    data class MyTopLevelMutation(
        var userPayload: UserPayload?
    )

    @DgsMutation
    fun myTopLevelMutation(): MyTopLevelMutation {
        return MyTopLevelMutation(null)
    }

    @DgsData(parentType = "MyTopLevelMutation", field = "topLevel")
    fun topLevel(@InputArgument input: UserInput): UserPayload {
        return UserPayload()
    }
}