External schema generation and Promises for Observables

[steffansluis]

I'm using an external library to generate part of my schema. The library support async resolvers but isn't aware they are allowed to be AsyncIterators/Observables, and as such I end up with strings saying [object Object] if I try to use Observables in the partially generated resolvers. As far as I can tell, this is because the library wraps the result in a Promise, resulting in an Observable wrapped in a Promise which is just interpreted as being a Promise resolving to an object.

I will probably end up solving this by fixing this myself on the library, but I was thinking this might be a broader problem that might be generally solvable by considering Promises for Observables to be a valid use case. Curious about your thoughts. 😃

[DxCx]

wait, so how the library "updates" ?
i mean, it returns a promise no if i got it right..

[steffansluis]

The library works by allowing you to provide a set of resolvers for different use-cases, each of which may return a Promise or not. The library then wraps the result of the resolvers in a Promise and does some processing before handing it off to GraphQL. Basically, I'd have to update the library anyway to fix the processing, but I think most of the processing doesn't affect the results, so the Observable I return from the resolvers it ending up in the proper place, it is just wrapped in a Promise.

I would guess many schema-generating tools work in a similar manner:

• Provide some resolver functions, async or not.
• Library does some connecting up, maybe some checking of results but usually no modification, except wrapping in Promise to ensure async things work correctly.
• Wrapping with prepareSchema breaks on Observables because they are also being wrapped in a Promise.