Fields are null when introspecting Input Types

[gordon-soh]

Hi, thanks for creating GraphQLite!

I have an issue when creating an Input Type - if we use introspection to inspect it the fields are always null.

I have tried creating an Input Type using the @Factory annotation, like so:

use TheCodingMachine\GraphQLite\Annotations\Factory;

class AddressInputType
{
    /**
     * @Factory(name="AddressInput", default=true)
     *
     * @param string $line1
     * @param string $postcode
     *
     * @return Address
     */
    public function createAddress(string $line1, string $postcode): Address
    {
        $address = new Address();
        $address->setLine1($line1);
        $address->setPostcode($postcode);
        return $address;
    }
}

And also using the @Input annotation from @devmaslov's PR (#269), like so:

use TheCodingMachine\GraphQLite\Annotations\Field;
use TheCodingMachine\GraphQLite\Annotations\Input;

/**
 * @Input(name="AddressInput", update=true)
 */
class AddressInputType
{
    /**
     * @Field()
     *
     * @var string
     */
    public string $line1;

    /**
     * @Field()
     *
     * @var string
     */
    public string $postcode;
}

But, when POSTing the following introspection query:

query {
    __type(name: "AddressInput") {
        name,
        fields {
            name,
            type {
                name
                kind
            }
        }
    }
}

The response is:

{
    "data": {
        "__type": {
            "name": "AddressInput",
            "fields": null
        }
    }
}

Is this is a bug, or am I doing something incorrectly here?

I can see the fields are being detected and added to the Input Type in InputTypeGenerator.php at line ~66 (mapInput()) but it looks like somewhere down the call-stack the fields are being set to null.

Any advice would be highly appreciated!

[gordon-soh]

It turns out this is actually correct - according to the GraphQL spec (https://github.com/graphql/graphql-spec/blob/main/spec/Section%204%20--%20Introspection.md), for INPUT_OBJECTs the fields should always be null and instead we should be looking at inputFields.

query {
    __type(name: "AddressInput") {
        name,
        inputFields {
            name,
            type {
                name
                kind
            }
        }
    }
}

The response is:

{
    "data": {
        "__type": {
            "name": "AddressInput",
            "inputFields": [
                {
                    "name": "line1",
                    "type": {
                        "name": null,
                        "kind": "NON_NULL"
                    }
                },
                {
                    "name": "postcode",
                    "type": {
                        "name": null,
                        "kind": "NON_NULL"
                    }
                }
            ]
        }
    }
}