GraphQL Custom Scalar Test Case

graphql.php

<?php

declare(strict_types=1);

// Run local test server
// php -S localhost:8080 graphql.php

// Try query
// curl -d '{"query": "query { echo(message: \"Hello World\") }" }' -H "Content-Type: application/json" http://localhost:8080

// Try mutation
// curl -d '{"query": "mutation { sum(x: 2, y: 2) }" }' -H "Content-Type: application/json" http://localhost:8080

require_once __DIR__ . '/../../vendor/autoload.php';

use GraphQL\GraphQL;
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\Type;
use GraphQL\Type\Schema;
use GraphQL\Type\Definition\ScalarType;
use GraphQL\Type\Definition\CustomScalarType;
use GraphQL\Language\AST\StringValueNode;
use GraphQL\Utils\Utils;
use GraphQL\Error\DebugFlag;
use GraphQL\Language\Parser;
use GraphQL\Utils\SchemaExtender;
use GraphQL\Error\Error;
use GraphQL\Error\SerializationError;
use GraphQL\Language\AST\Node;


class EmailType extends ScalarType
{
    public function serialize($value): string
    {
        error_log('true');

        if (!$this->isEmail($value)) {
            throw new SerializationError('Cannot represent value as email: ' . Utils::printSafe($value));
        }

        return $value;
    }

    public function parseValue($value): string
    {
        if (!$this->isEmail($value)) {
            throw new Error('Cannot represent value as email: ' . Utils::printSafe($value));
        }

        return $value;
    }

    public function parseLiteral(Node $valueNode, ?array $variables = null): string
    {
        // Note: throwing GraphQL\Error\Error vs \UnexpectedValueException to benefit from GraphQL
        // error location in query:
        if (!$valueNode instanceof StringValueNode) {
            throw new Error('Query error: Can only parse strings got: ' . $valueNode->kind, [$valueNode]);
        }

        $value = $valueNode->value;
        if (!$this->isEmail($value)) {
            throw new Error('Not a valid email', [$valueNode]);
        }

        return $value;
    }

    /**
     * Is the value a valid email?
     *
     * @param mixed $value
     */
    private function isEmail($value): bool
    {
        return filter_var($value, FILTER_VALIDATE_EMAIL) !== false;
    }
}

$customEmailType = new CustomScalarType([
    'name' => 'Email',
    'serialize' => static function ($value) {
        if (!filter_var($value, FILTER_VALIDATE_EMAIL)) {
            throw new InvariantViolation("Could not serialize following value as email: " . Utils::printSafe($value));
        }


        if (!filter_var($value, FILTER_VALIDATE_EMAIL)) {
            throw new Error("Cannot represent following value as email: " . Utils::printSafeJson($value));
        }

        return $value;
    },
    'parseValue' => static function ($value) {
        if (!filter_var($value, FILTER_VALIDATE_EMAIL)) {
            throw new Error("Cannot represent following value as email: " . Utils::printSafeJson($value));
        }

        return $value;
    },
    'parseLiteral' => static function (Node $valueNode, ?array $variables = null) {
        if (!$valueNode instanceof StringValueNode) {
            throw new Error('Query error: Can only parse strings got: ' . $valueNode->kind, [$valueNode]);
        }

        if (!filter_var($valueNode->value, FILTER_VALIDATE_EMAIL)) {
            throw new Error("Not a valid email", [$valueNode]);
        }

        return $valueNode->value;
    },
]);

try {
    $emailType = new EmailType();
    //WORKS.
    // $emailType = $customEmailType;

    $userType = new ObjectType([
        'name' => 'User',
        'fields' => [
            'userName' => Type::string(),
            'email' => $emailType,
        ]
    ]);

    $queryType = new ObjectType([
        'name' => 'Query',
        'fields' => [
            'user' => [
                'type' => $userType,
            ],
        ],
    ]);

    $gql = '
    extend type Query {
        users: [User]
      }
      ';

    $schema = new Schema([
        'query' => $queryType,
    ]);



    $documentNode = Parser::parse($gql);

    //COMMENT THIS OUT FOR EMAIL TO WORK.
    $schema = SchemaExtender::extend($schema, $documentNode, []);


    $rawInput       = file_get_contents('php://input');
    $input          = json_decode($rawInput, true);
    $query          = $input['query'];
    $variableValues = $input['variables'] ?? null;
    $debug = DebugFlag::INCLUDE_DEBUG_MESSAGE;

    $rootValue = [
        'user' => [
            'userName' => 'test_user',
            'email' => 'test@test.com'
        ],
        'users' => [
            [
                'userName' => 'test_user1',
                'email' => 'test1@test.com'
            ],
            [
                'userName' => 'test_user2',
                'email' => 'test2@test.com'
            ]
        ]
    ];
    $result    = GraphQL::executeQuery($schema, $query, $rootValue, null, $variableValues);
    $output    = $result->toArray($debug);
} catch (Throwable $e) {
    $output = [
        'error' => [
            'message' => $e->getMessage(),
        ],
    ];
}

header('Content-Type: application/json; charset=UTF-8');
echo json_encode($output);