Could not infer return type...

[renehauck]

Hi,

first, I will thank you for this awesome package. 👍
Currently we are start a new project and would like to implement this package (and give you feedback, if you like).
I think I found the first bug 😉.
My code:

import { Schema, Query, ObjectType, Field, Mutation, compileSchema } from 'typegql';

@ObjectType({ description: 'Simple product object type' })
class Product {
    @Field()
    isExpensive() {
        return this.price > 50;
    }
    @Field() name: string;

    @Field() price: number;

}

@Schema()
class SuperSchema {
    @Query()
    hello(): Product {
        return new Product();
    }
}

export const compiledSchema = compileSchema(SuperSchema);

Errostack:

        return _super !== null && _super.apply(this, arguments) || this;
                                         ^
Error: @ObjectType Product.isExpensive: Could not infer return type and no type is forced. In case of circular dependencies make sure to force types of instead of infering them.
source-map-support.js:439
    at FieldError.BaseError [as constructor] (/home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:280:42)
    at new FieldError (/home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:710:24)
    at inferTypeOrThrow (/home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:421:15)
    at resolveRegisteredOrInferedType (/home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:641:12)
    at compileFieldConfig$$1 (/home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:659:24)
    at /home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:692:39
    at Array.forEach (<anonymous>)
    at getAllFields (/home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:687:25)
    at /home/rene/Projects/jennyjs/node_modules/typegql/lib/index.js:700:39
    at Array.forEach (<anonymous>)

Is this a Bug, or what I'm doing wrong?
Thanks

[MichalLytek]

this is behaving as intended. we only serialize explicit types. implicit types are not serialized. this is the only way to make scenarios like single-file transpile works.

microsoft/TypeScript#18995

[renehauck]

very fast...thank you

[pie6k]

Right, you need to be explicit about return type of function. In your case you'd need to tell it returns boolean even if it's obvious in function code.

    isExpensive(): boolean { // <-- `boolean` return type is explicit here and that's needed for typegql to know it
        return this.price > 50;
    }

[cgatian]

Doesnt the documentation show using implicit types?

  @Field()
  isExpensive() { // <--- Missing boolean
    return this.price > 50;
  }