Null bubbles up to non-nullable array element

[edsrzf]

What happened?

I've defined a field in my schema that is an array of non-null elements ([T!]!). When an error occurs resolving one of the elements of the array, the null bubbles up to the element of the array rather than the next nullable field.

What did you expect?

Non-nullable elements should never be null. I expect the null to bubble up to the next nullable field, as defined in the specification.

Minimal graphql.schema and models to reproduce

There's a full repo with instructions here: https://github.com/edsrzf/gqlgen-null-repro

Schema:

type Todo {
  user: User!
}

type User {
  name: String!
}

type Query {
  todos: [Todo!]!
}

Resolvers:

package gqlgen_repro

import (
	"context"
	"errors"
)

type Resolver struct{}

func (r *Resolver) Query() QueryResolver {
	return &queryResolver{r}
}

func (r *Resolver) Todo() TodoResolver {
	return &todoResolver{r}
}

type queryResolver struct{ *Resolver }

func (r *queryResolver) Todos(ctx context.Context) ([]*Todo, error) {
	return []*Todo{{}}, nil
}

type todoResolver struct{ *Resolver }

func (r *todoResolver) User(ctx context.Context, obj *Todo) (*User, error) {
	return nil, errors.New("oh no")
}

I used the models generated by gqlgen, but forced Todo.user to use a resolver.

versions

• gqlgen version? 0.9.1
• go version? 1.12.6
• dep or go modules? Go modules

[vvakame]

I confirmed this issue still occurred in v0.10.2 and master/HEAD (v0.10.3-0.20191128123652-f869f5a85385)

[NaLLiFFuNT]

any updates?

[wilhelmeek]

I've raised a PR that addresses this behaviour here #1480. Not sure who the best people to loop in are though?

[wilhelmeek]

The above PR's been merged, so this issue should now be resolved.

[arash16]

So is there going to be a new patch release? It's been months past by?!