Cannot return null for non-nullable field

Hi,

I'm new with GraphQL and maybe doing something wrong.

I have this query:

getTapeLanguages(tapeId:112830){
    languageId
    name
    createdAt
  }

Query type is something like this

'type' => Type::listOf($types->getOutput(Language::class))

And resolver return this

$tape->getLanguages()->toArray()

While getLanguages()->count() is equal to 1 and getLanguages()->current()->getLanguageId() return 12 (expected value) I get this error:

Cannot return null for non-nullable field Language.languageId.

What I'm doing wrong? Resolver could return a Language Collection as array and is it supported?

Regards

The default resolver provided by this lib should be able to resolve getters of objects in an array. But it seems you are not giving an array but a collection of some sort. Maybe an ArrayObject ?

You should double check that and either write your own resolver or return a real array.

See

graphql-doctrine/src/DefaultFieldResolver.php

Line 28 in 1e11044

} elseif (is_array($source) || $source instanceof ArrayAccess) {

I will check but put in this

return [$tape->getLanguages()->current()]

instead of

return $tape->getLanguages()->toArray()

Also output same error.

Thanks!

This is a bit of a blind guess, but you should try validating your schema (in your unit tests) with the \GraphQL\Type\Schema::assertValid() method. Just to be sure your schema makes sense.

My bad, I was missing

GraphQL::setDefaultFieldResolver(new DefaultFieldResolver());

Regards