Proposal: Add support for extends

[4F2E4A2E]

Please add support for object extension.

@GraphQLObjectType()
abstract class B {
    @Field()
    b: string;
}

@GraphQLObjectType()
abstract class A extends B {
    @Field()
    a: string;
}


@GraphQLResolver(() => TestResolver)
class TestResolver {

    @Query(returnType => A, {description: ''})
    test() {
        return {
            a: 'a-value',
            b: 'b-value'
        };
    }
}

Expected result:

{"data":{"test":{"a":"a-value","b":"b-value"}}}

Actual result:

{"errors":[{"message":"Cannot query field \"b\" on type \"A\". Did you mean \"a\"?","locations":[{"line":1,"column":9}]}]}

[MichalLytek]

It will be a part of #6 - I have to develop mechanism for looking up on other definitions for fields info.
Closing in favour of that issue 😉

[4F2E4A2E]

I am happy to contribute 😉