graphql-java-tools Unable to find class for union type

com.coxautodev.graphql.tools.SchemaClassScannerError: Object type 'WeirdPet' is a member of a 
  known union, but no class could be found for that type name.

my schema

union Pet =  NormalPet | WeirdPet

type WeirdPet {
    id: Int
    name: String
    age: Int
    classification: Classification
    availableDate: Date
}

type NormalPet {
    id: Int
    type: Animal
    name: String
    age: Int
    owner: Owner
    availableDate: Date
}

type Query {
    pets: [Pet]
}

Spring boot class

@ComponentScan
@EnableAutoConfiguration
@SpringBootApplication
public class AppGraphql {
    public static void main(String[] args) {
        SpringApplication.run(AppGraphql.class, args);

    }
    @Bean
    public GraphQLSchema schema() {
        return SchemaParser.newParser()
                .files("petshop.graphqls", "Types.graphqls", "InputTypes.graphqls")
                .resolvers(new Query(), new Mutation(), new Subscription(new NewsPublisher()))
                .scalars(new ScalarDate())
                .dictionary("WeirdPet", WeirdPet.class)
                .build().makeExecutableSchema();
    }
}

Oct 30 '18 06:10 orvillelim

Found workaround in issue by making sure there's either query request or mutation request defined in schema that returns WeirdPet type

Before :

type Query {
    pets: [Pet]
    owner(id: Int): Owner
    getAdoptablePet: [NormalPet]
    getAdoptableWeirdPet: [NormalPet]
}

type Mutation {
    createPet(name: String, age: Int, type: Animal, owner: OwnerInput) : NormalPet
    addForAdoptPet(name: String, age: Int, type: Animal, availableDate: Date) : NormalPet
}

After

type Query {
    pets: [Pet]
    owner(id: Int): Owner
    getAdoptablePet: [Pet]
    getAdoptableWeirdPet: [WeirdPet]
}

type Mutation {
    createPet(name: String, age: Int, type: Animal, owner: OwnerInput) : NormalPet
    addForAdoptPet(name: String, age: Int, type: Animal, availableDate: Date) : NormalPet
    addForAdoptPet(name: String, age: Int, classification: Classification, availableDate: Date) : WeirdPet
}

Oct 30 '18 19:10 orvillelim

I guess we should still able to create union without creating a "request" that returns the specific union type in this case "WeirdPet" type. Is this a bug?

Oct 30 '18 19:10 orvillelim

@villerdex Was facing similar issue and was able to solve by creating a bean of SchemaParserDictionary with union member classes. With your schema, it would look like:

   @Bean
    public SchemaParserDictionary getSchemaParser() {
        SchemaParserDictionary dictionary = new SchemaParserDictionary();
        dictionary.add(new HashMap() {{
                put("WierdPet", WeirdPet.class);
                put("NormalPet", NormalPet.class);
        }});
        return dictionary;
    }

Nov 09 '18 08:11 amimehra

@villerdex Right now it searches for the types starting at the root resolvers. That could be improved by taking the union definition into account as well.

Nov 17 '18 13:11 oliemansm

Same thing seems to happen for interfaces:

"Object type MyType implements a known interface, but no class could be found for that type name. Please pass a class for type MyType in the parser's dictionary."