Refactoring

src/Executor/ExecutionContext.php

@@ -1,7 +1,11 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor;
 
 use GraphQL\Error\Error;
+use GraphQL\Executor\Promise\PromiseAdapter;
 use GraphQL\Language\AST\FragmentDefinitionNode;
 use GraphQL\Language\AST\OperationDefinitionNode;
 use GraphQL\Type\Schema;
@@ -16,46 +20,33 @@ use GraphQL\Type\Schema;
  */
 class ExecutionContext
 {
-    /**
+    /** @var Schema */
-     * @var Schema
-     */
     public $schema;
 
-    /**
+    /** @var FragmentDefinitionNode[] */
-     * @var FragmentDefinitionNode[]
-     */
     public $fragments;
 
-    /**
+    /** @var mixed */
-     * @var mixed
-     */
     public $rootValue;
 
-    /**
+    /** @var mixed */
-     * @var mixed
-     */
     public $contextValue;
 
-    /**
+    /** @var OperationDefinitionNode */
-     * @var OperationDefinitionNode
-     */
     public $operation;
 
-    /**
+    /** @var mixed[] */
-     * @var array
-     */
     public $variableValues;
 
-    /**
+    /** @var callable */
-     * @var callable
-     */
     public $fieldResolver;
 
-    /**
+    /** @var Error[] */
-     * @var array
-     */
     public $errors;
 
+    /** @var PromiseAdapter */
+    public $promises;
+
     public function __construct(
         $schema,
         $fragments,
@@ -66,8 +57,7 @@ class ExecutionContext
         $errors,
         $fieldResolver,
         $promiseAdapter
-    )
+    ) {
-    {
         $this->schema         = $schema;
         $this->fragments      = $fragments;
         $this->rootValue      = $root;
@@ -82,6 +72,7 @@ class ExecutionContext
     public function addError(Error $error)
     {
         $this->errors[] = $error;
+
         return $this;
     }
 }

src/Executor/ExecutionResult.php

@@ -1,7 +1,12 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor;
 
+use GraphQL\Error\Error;
 use GraphQL\Error\FormattedError;
+use function array_map;
 
 /**
  * Returned after [query execution](executing-queries.md).
@@ -17,7 +22,7 @@ class ExecutionResult implements \JsonSerializable
      * Data collected from resolvers during query execution
      *
      * @api
-     * @var array
+     * @var mixed[]
      */
     public $data;
 
@@ -28,7 +33,7 @@ class ExecutionResult implements \JsonSerializable
      * contain original exception.
      *
      * @api
-     * @var \GraphQL\Error\Error[]
+     * @var Error[]
      */
     public $errors;
 
@@ -37,26 +42,22 @@ class ExecutionResult implements \JsonSerializable
      * Conforms to
      *
      * @api
-     * @var array
+     * @var mixed[]
      */
     public $extensions;
 
-    /**
+    /** @var callable */
-     * @var callable
-     */
     private $errorFormatter;
 
-    /**
+    /** @var callable */
-     * @var callable
-     */
     private $errorsHandler;
 
     /**
-     * @param array $data
+     * @param mixed[] $data
-     * @param array $errors
+     * @param Error[] $errors
-     * @param array $extensions
+     * @param mixed[] $extensions
      */
-    public function __construct(array $data = null, array $errors = [], array $extensions = [])
+    public function __construct(?array $data = null, array $errors = [], array $extensions = [])
     {
         $this->data       = $data;
         $this->errors     = $errors;
@@ -77,12 +78,12 @@ class ExecutionResult implements \JsonSerializable
      * );
      *
      * @api
-     * @param callable $errorFormatter
      * @return $this
      */
     public function setErrorFormatter(callable $errorFormatter)
     {
         $this->errorFormatter = $errorFormatter;
+
         return $this;
     }
 
@@ -97,15 +98,23 @@ class ExecutionResult implements \JsonSerializable
      * }
      *
      * @api
-     * @param callable $handler
      * @return $this
      */
     public function setErrorsHandler(callable $handler)
     {
         $this->errorsHandler = $handler;
+
         return $this;
     }
 
+    /**
+     * @return mixed[]
+     */
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
+
     /**
      * Converts GraphQL query result to spec-compliant serializable array using provided
      * errors handler and formatter.
@@ -118,40 +127,31 @@ class ExecutionResult implements \JsonSerializable
      *
      * @api
      * @param bool|int $debug
-     * @return array
+     * @return mixed[]
      */
     public function toArray($debug = false)
     {
         $result = [];
 
-        if (!empty($this->errors)) {
+        if (! empty($this->errors)) {
-            $errorsHandler = $this->errorsHandler ?: function(array $errors, callable $formatter) {
+            $errorsHandler = $this->errorsHandler ?: function (array $errors, callable $formatter) {
                 return array_map($formatter, $errors);
             };
+
             $result['errors'] = $errorsHandler(
                 $this->errors,
                 FormattedError::prepareFormatter($this->errorFormatter, $debug)
             );
         }
 
-        if (null !== $this->data) {
+        if ($this->data !== null) {
             $result['data'] = $this->data;
         }
 
-        if (!empty($this->extensions)) {
+        if (! empty($this->extensions)) {
             $result['extensions'] = (array) $this->extensions;
         }
 
         return $result;
     }
-
-    /**
-     * Part of \JsonSerializable interface
-     *
-     * @return array
-     */
-    public function jsonSerialize()
-    {
-        return $this->toArray();
-    }
 }

src/Executor/Promise/Adapter/ReactPromiseAdapter.php

@@ -1,4 +1,7 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor\Promise\Adapter;
 
 use GraphQL\Executor\Promise\Promise;
@@ -6,6 +9,9 @@ use GraphQL\Executor\Promise\PromiseAdapter;
 use GraphQL\Utils\Utils;
 use React\Promise\Promise as ReactPromise;
 use React\Promise\PromiseInterface as ReactPromiseInterface;
+use function React\Promise\all;
+use function React\Promise\reject;
+use function React\Promise\resolve;
 
 class ReactPromiseAdapter implements PromiseAdapter
 {
@@ -28,10 +34,11 @@ class ReactPromiseAdapter implements PromiseAdapter
     /**
      * @inheritdoc
      */
-    public function then(Promise $promise, callable $onFulfilled = null, callable $onRejected = null)
+    public function then(Promise $promise, ?callable $onFulfilled = null, ?callable $onRejected = null)
     {
-        /** @var $adoptedPromise ReactPromiseInterface */
+        /** @var ReactPromiseInterface $adoptedPromise */
         $adoptedPromise = $promise->adoptedPromise;
+
         return new Promise($adoptedPromise->then($onFulfilled, $onRejected), $this);
     }
 
@@ -41,6 +48,7 @@ class ReactPromiseAdapter implements PromiseAdapter
     public function create(callable $resolver)
     {
         $promise = new ReactPromise($resolver);
+
         return new Promise($promise, $this);
     }
 
@@ -49,7 +57,8 @@ class ReactPromiseAdapter implements PromiseAdapter
      */
     public function createFulfilled($value = null)
     {
-        $promise = \React\Promise\resolve($value);
+        $promise = resolve($value);
+
         return new Promise($promise, $this);
     }
 
@@ -58,7 +67,8 @@ class ReactPromiseAdapter implements PromiseAdapter
      */
     public function createRejected($reason)
     {
-        $promise = \React\Promise\reject($reason);
+        $promise = reject($reason);
+
         return new Promise($promise, $this);
     }
 
@@ -68,11 +78,14 @@ class ReactPromiseAdapter implements PromiseAdapter
     public function all(array $promisesOrValues)
     {
         // TODO: rework with generators when PHP minimum required version is changed to 5.5+
-        $promisesOrValues = Utils::map($promisesOrValues, function ($item) {
+        $promisesOrValues = Utils::map(
+            $promisesOrValues,
+            function ($item) {
                 return $item instanceof Promise ? $item->adoptedPromise : $item;
-        });
+            }
+        );
 
-        $promise = \React\Promise\all($promisesOrValues)->then(function($values) use ($promisesOrValues) {
+        $promise = all($promisesOrValues)->then(function ($values) use ($promisesOrValues) {
             $orderedResults = [];
 
             foreach ($promisesOrValues as $key => $value) {
@@ -81,6 +94,7 @@ class ReactPromiseAdapter implements PromiseAdapter
 
             return $orderedResults;
         });
+
         return new Promise($promise, $this);
     }
 }

src/Executor/Promise/Adapter/SyncPromise.php

@@ -1,15 +1,20 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor\Promise\Adapter;
 
+use GraphQL\Executor\ExecutionResult;
 use GraphQL\Utils\Utils;
+use Throwable;
+use function is_object;
+use function method_exists;
 
 /**
  * Class SyncPromise
  *
  * Simplistic (yet full-featured) implementation of Promises A+ spec for regular PHP `sync` mode
  * (using queue to defer promises execution)
- *
- * @package GraphQL\Executor\Promise\Adapter
  */
 class SyncPromise
 {
@@ -17,38 +22,69 @@ class SyncPromise
     const FULFILLED = 'fulfilled';
     const REJECTED  = 'rejected';
 
-    /**
+    /** @var \SplQueue */
-     * @var \SplQueue
-     */
     public static $queue;
 
-    public static function getQueue()
+    /** @var string */
-    {
+    public $state = self::PENDING;
-        return self::$queue ?: self::$queue = new \SplQueue();
+
-    }
+    /** @var ExecutionResult|Throwable */
+    public $result;
+
+    /**
+     * Promises created in `then` method of this promise and awaiting for resolution of this promise
+     * @var mixed[][]
+     */
+    private $waiting = [];
 
     public static function runQueue()
     {
         $q = self::$queue;
-        while ($q && !$q->isEmpty()) {
+        while ($q && ! $q->isEmpty()) {
             $task = $q->dequeue();
             $task();
         }
     }
 
-    public $state = self::PENDING;
+    public function resolve($value)
+    {
+        switch ($this->state) {
+            case self::PENDING:
+                if ($value === $this) {
+                    throw new \Exception('Cannot resolve promise with self');
+                }
+                if (is_object($value) && method_exists($value, 'then')) {
+                    $value->then(
+                        function ($resolvedValue) {
+                            $this->resolve($resolvedValue);
+                        },
+                        function ($reason) {
+                            $this->reject($reason);
+                        }
+                    );
 
-    public $result;
+                    return $this;
+                }
 
-    /**
+                $this->state  = self::FULFILLED;
-     * Promises created in `then` method of this promise and awaiting for resolution of this promise
+                $this->result = $value;
-     * @var array
+                $this->enqueueWaitingPromises();
-     */
+                break;
-    private $waiting = [];
+            case self::FULFILLED:
+                if ($this->result !== $value) {
+                    throw new \Exception('Cannot change value of fulfilled promise');
+                }
+                break;
+            case self::REJECTED:
+                throw new \Exception('Cannot resolve rejected promise');
+        }
+
+        return $this;
+    }
 
     public function reject($reason)
     {
-        if (!$reason instanceof \Exception && !$reason instanceof \Throwable) {
+        if (! $reason instanceof \Exception && ! $reason instanceof \Throwable) {
             throw new \Exception('SyncPromise::reject() has to be called with an instance of \Throwable');
         }
 
@@ -60,70 +96,22 @@ class SyncPromise
                 break;
             case self::REJECTED:
                 if ($reason !== $this->result) {
-                    throw new \Exception("Cannot change rejection reason");
+                    throw new \Exception('Cannot change rejection reason');
                 }
                 break;
             case self::FULFILLED:
-                throw new \Exception("Cannot reject fulfilled promise");
+                throw new \Exception('Cannot reject fulfilled promise');
-        }
-        return $this;
         }
 
-    public function resolve($value)
-    {
-        switch ($this->state) {
-            case self::PENDING:
-                if ($value === $this) {
-                    throw new \Exception("Cannot resolve promise with self");
-                }
-                if (is_object($value) && method_exists($value, 'then')) {
-                    $value->then(
-                        function($resolvedValue) {
-                            $this->resolve($resolvedValue);
-                        },
-                        function($reason) {
-                            $this->reject($reason);
-                        }
-                    );
         return $this;
     }
 
-                $this->state = self::FULFILLED;
-                $this->result = $value;
-                $this->enqueueWaitingPromises();
-                break;
-            case self::FULFILLED:
-                if ($this->result !== $value) {
-                    throw new \Exception("Cannot change value of fulfilled promise");
-                }
-                break;
-            case self::REJECTED:
-                throw new \Exception("Cannot resolve rejected promise");
-        }
-        return $this;
-    }
-
-    public function then(callable $onFulfilled = null, callable $onRejected = null)
-    {
-        if ($this->state === self::REJECTED && !$onRejected) {
-            return $this;
-        }
-        if ($this->state === self::FULFILLED && !$onFulfilled) {
-            return $this;
-        }
-        $tmp = new self();
-        $this->waiting[] = [$tmp, $onFulfilled, $onRejected];
-
-        if ($this->state !== self::PENDING) {
-            $this->enqueueWaitingPromises();
-        }
-
-        return $tmp;
-    }
-
     private function enqueueWaitingPromises()
     {
-        Utils::invariant($this->state !== self::PENDING, 'Cannot enqueue derived promises when parent is still pending');
+        Utils::invariant(
+            $this->state !== self::PENDING,
+            'Cannot enqueue derived promises when parent is still pending'
+        );
 
         foreach ($this->waiting as $descriptor) {
             self::getQueue()->enqueue(function () use ($descriptor) {
@@ -138,7 +126,7 @@ class SyncPromise
                     } catch (\Throwable $e) {
                         $promise->reject($e);
                     }
-                } else if ($this->state === self::REJECTED) {
+                } elseif ($this->state === self::REJECTED) {
                     try {
                         if ($onRejected) {
                             $promise->resolve($onRejected($this->result));
@@ -155,4 +143,27 @@ class SyncPromise
         }
         $this->waiting = [];
     }
+
+    public static function getQueue()
+    {
+        return self::$queue ?: self::$queue = new \SplQueue();
+    }
+
+    public function then(?callable $onFulfilled = null, ?callable $onRejected = null)
+    {
+        if ($this->state === self::REJECTED && ! $onRejected) {
+            return $this;
+        }
+        if ($this->state === self::FULFILLED && ! $onFulfilled) {
+            return $this;
+        }
+        $tmp             = new self();
+        $this->waiting[] = [$tmp, $onFulfilled, $onRejected];
+
+        if ($this->state !== self::PENDING) {
+            $this->enqueueWaitingPromises();
+        }
+
+        return $tmp;
+    }
 }

src/Executor/Promise/Adapter/SyncPromiseAdapter.php

@@ -1,19 +1,20 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor\Promise\Adapter;
 
 use GraphQL\Deferred;
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Executor\ExecutionResult;
 use GraphQL\Executor\Promise\Promise;
 use GraphQL\Executor\Promise\PromiseAdapter;
 use GraphQL\Utils\Utils;
+use function count;
 
 /**
- * Class SyncPromiseAdapter
- *
  * Allows changing order of field resolution even in sync environments
  * (by leveraging queue of deferreds and promises)
- *
- * @package GraphQL\Executor\Promise\Adapter
  */
 class SyncPromiseAdapter implements PromiseAdapter
 {
@@ -30,20 +31,22 @@ class SyncPromiseAdapter implements PromiseAdapter
      */
     public function convertThenable($thenable)
     {
-        if (!$thenable instanceof Deferred) {
+        if (! $thenable instanceof Deferred) {
             throw new InvariantViolation('Expected instance of GraphQL\Deferred, got ' . Utils::printSafe($thenable));
         }
+
         return new Promise($thenable->promise, $this);
     }
 
     /**
      * @inheritdoc
      */
-    public function then(Promise $promise, callable $onFulfilled = null, callable $onRejected = null)
+    public function then(Promise $promise, ?callable $onFulfilled = null, ?callable $onRejected = null)
     {
-        /** @var SyncPromise $promise */
+        /** @var SyncPromise $adoptedPromise */
-        $promise = $promise->adoptedPromise;
+        $adoptedPromise = $promise->adoptedPromise;
-        return new Promise($promise->then($onFulfilled, $onRejected), $this);
+
+        return new Promise($adoptedPromise->then($onFulfilled, $onRejected), $this);
     }
 
     /**
@@ -55,8 +58,14 @@ class SyncPromiseAdapter implements PromiseAdapter
 
         try {
             $resolver(
-                [$promise, 'resolve'],
+                [
-                [$promise, 'reject']
+                    $promise,
+                    'resolve',
+                ],
+                [
+                    $promise,
+                    'reject',
+                ]
             );
         } catch (\Exception $e) {
             $promise->reject($e);
@@ -73,6 +82,7 @@ class SyncPromiseAdapter implements PromiseAdapter
     public function createFulfilled($value = null)
     {
         $promise = new SyncPromise();
+
         return new Promise($promise->resolve($value), $this);
     }
 
@@ -82,6 +92,7 @@ class SyncPromiseAdapter implements PromiseAdapter
     public function createRejected($reason)
     {
         $promise = new SyncPromise();
+
         return new Promise($promise->reject($reason), $this);
     }
 
@@ -100,12 +111,14 @@ class SyncPromiseAdapter implements PromiseAdapter
             if ($promiseOrValue instanceof Promise) {
                 $result[$index] = null;
                 $promiseOrValue->then(
-                    function($value) use ($index, &$count, $total, &$result, $all) {
+                    function ($value) use ($index, &$count, $total, &$result, $all) {
                         $result[$index] = $value;
                         $count++;
-                        if ($count >= $total) {
+                        if ($count < $total) {
-                            $all->resolve($result);
+                            return;
                         }
+
+                        $all->resolve($result);
                     },
                     [$all, 'reject']
                 );
@@ -117,14 +130,14 @@ class SyncPromiseAdapter implements PromiseAdapter
         if ($count === $total) {
             $all->resolve($result);
         }
+
         return new Promise($all, $this);
     }
 
     /**
      * Synchronously wait when promise completes
      *
-     * @param Promise $promise
+     * @return ExecutionResult
-     * @return mixed
      */
     public function wait(Promise $promise)
     {
@@ -132,9 +145,8 @@ class SyncPromiseAdapter implements PromiseAdapter
         $dfdQueue     = Deferred::getQueue();
         $promiseQueue = SyncPromise::getQueue();
 
-        while (
+        while ($promise->adoptedPromise->state === SyncPromise::PENDING &&
-            $promise->adoptedPromise->state === SyncPromise::PENDING &&
+            ! ($dfdQueue->isEmpty() && $promiseQueue->isEmpty())
-            !($dfdQueue->isEmpty() && $promiseQueue->isEmpty())
         ) {
             Deferred::runQueue();
             SyncPromise::runQueue();
@@ -146,17 +158,16 @@ class SyncPromiseAdapter implements PromiseAdapter
 
         if ($syncPromise->state === SyncPromise::FULFILLED) {
             return $syncPromise->result;
-        } else if ($syncPromise->state === SyncPromise::REJECTED) {
+        } elseif ($syncPromise->state === SyncPromise::REJECTED) {
             throw $syncPromise->result;
         }
 
-        throw new InvariantViolation("Could not resolve promise");
+        throw new InvariantViolation('Could not resolve promise');
     }
 
     /**
      * Execute just before starting to run promise completion
      *
-     * @param Promise $promise
      */
     protected function beforeWait(Promise $promise)
     {
@@ -165,7 +176,6 @@ class SyncPromiseAdapter implements PromiseAdapter
     /**
      * Execute while running promise completion
      *
-     * @param Promise $promise
      */
     protected function onWait(Promise $promise)
     {

src/Executor/Promise/Promise.php

@@ -1,6 +1,10 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor\Promise;
 
+use GraphQL\Executor\Promise\Adapter\SyncPromise;
 use GraphQL\Utils\Utils;
 
 /**
@@ -8,31 +12,28 @@ use GraphQL\Utils\Utils;
  */
 class Promise
 {
-    private $adapter;
+    /** @var SyncPromise|ReactPromise */
-
     public $adoptedPromise;
 
+    /** @var PromiseAdapter */
+    private $adapter;
+
     /**
-     * Promise constructor.
-     *
      * @param mixed $adoptedPromise
-     * @param PromiseAdapter $adapter
      */
     public function __construct($adoptedPromise, PromiseAdapter $adapter)
     {
-        Utils::invariant(!$adoptedPromise instanceof self, 'Expecting promise from adapted system, got ' . __CLASS__);
+        Utils::invariant(! $adoptedPromise instanceof self, 'Expecting promise from adapted system, got ' . __CLASS__);
 
         $this->adapter        = $adapter;
         $this->adoptedPromise = $adoptedPromise;
     }
 
     /**
-     * @param callable|null $onFulfilled
-     * @param callable|null $onRejected
      *
      * @return Promise
      */
-    public function then(callable $onFulfilled = null, callable $onRejected = null)
+    public function then(?callable $onFulfilled = null, ?callable $onRejected = null)
     {
         return $this->adapter->then($this, $onFulfilled, $onRejected);
     }

src/Executor/Promise/PromiseAdapter.php

@@ -1,4 +1,7 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor\Promise;
 
 /**
@@ -29,13 +32,10 @@ interface PromiseAdapter
      * in Promises/A+ specs. Then returns new wrapped instance of GraphQL\Executor\Promise\Promise.
      *
      * @api
-     * @param Promise $promise
-     * @param callable|null $onFulfilled
-     * @param callable|null $onRejected
      *
      * @return Promise
      */
-    public function then(Promise $promise, callable $onFulfilled = null, callable $onRejected = null);
+    public function then(Promise $promise, ?callable $onFulfilled = null, ?callable $onRejected = null);
 
     /**
      * Creates a Promise
@@ -44,7 +44,6 @@ interface PromiseAdapter
      *     function(callable $resolve, callable $reject)
      *
      * @api
-     * @param callable $resolver
      * @return Promise
      */
     public function create(callable $resolver);
@@ -73,7 +72,7 @@ interface PromiseAdapter
      * items in the array are fulfilled.
      *
      * @api
-     * @param array $promisesOrValues Promises or values.
+     * @param Promise[]|mixed[] $promisesOrValues Promises or values.
      * @return Promise
      */
     public function all(array $promisesOrValues);

src/Executor/Values.php

@@ -1,4 +1,7 @@
 <?php
+
+declare(strict_types=1);
+
 namespace GraphQL\Executor;
 
 use GraphQL\Error\Error;
@@ -10,19 +13,24 @@ use GraphQL\Language\AST\FieldNode;
 use GraphQL\Language\AST\FragmentSpreadNode;
 use GraphQL\Language\AST\InlineFragmentNode;
 use GraphQL\Language\AST\NodeList;
-use GraphQL\Language\AST\VariableNode;
+use GraphQL\Language\AST\ValueNode;
 use GraphQL\Language\AST\VariableDefinitionNode;
+use GraphQL\Language\AST\VariableNode;
 use GraphQL\Language\Printer;
-use GraphQL\Type\Schema;
 use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\FieldDefinition;
 use GraphQL\Type\Definition\InputType;
 use GraphQL\Type\Definition\NonNull;
 use GraphQL\Type\Definition\Type;
+use GraphQL\Type\Schema;
 use GraphQL\Utils\AST;
 use GraphQL\Utils\TypeInfo;
 use GraphQL\Utils\Utils;
 use GraphQL\Utils\Value;
+use Throwable;
+use function array_key_exists;
+use function array_map;
+use function sprintf;
 
 class Values
 {
@@ -31,10 +39,9 @@ class Values
      * variable definitions and arbitrary input. If the input cannot be coerced
      * to match the variable definitions, a Error will be thrown.
      *
-     * @param Schema $schema
      * @param VariableDefinitionNode[] $varDefNodes
-     * @param array $inputs
+     * @param mixed[]                  $inputs
-     * @return array
+     * @return mixed[]
      */
     public static function getVariableValues(Schema $schema, $varDefNodes, array $inputs)
     {
@@ -45,21 +52,27 @@ class Values
             /** @var InputType|Type $varType */
             $varType = TypeInfo::typeFromAST($schema, $varDefNode->type);
 
-            if (!Type::isInputType($varType)) {
+            if (! Type::isInputType($varType)) {
                 $errors[] = new Error(
-                    "Variable \"\$$varName\" expected value of type " .
+                    sprintf(
-                    '"' . Printer::doPrint($varDefNode->type) . '" which cannot be used as an input type.',
+                        'Variable "$%s" expected value of type "%s" which cannot be used as an input type.',
+                        $varName,
+                        Printer::doPrint($varDefNode->type)
+                    ),
                     [$varDefNode->type]
                 );
             } else {
-                if (!array_key_exists($varName, $inputs)) {
+                if (! array_key_exists($varName, $inputs)) {
                     if ($varType instanceof NonNull) {
                         $errors[] = new Error(
-                            "Variable \"\$$varName\" of required type " .
+                            sprintf(
-                            "\"{$varType}\" was not provided.",
+                                'Variable "$%s" of required type "%s" was not provided.',
+                                $varName,
+                                $varType
+                            ),
                             [$varDefNode]
                         );
-                    } else if ($varDefNode->defaultValue) {
+                    } elseif ($varDefNode->defaultValue) {
                         $coercedValues[$varName] = AST::valueFromAST($varDefNode->defaultValue, $varType);
                     }
                 } else {
@@ -67,10 +80,14 @@ class Values
                     $coerced = Value::coerceValue($value, $varType, $varDefNode);
                     /** @var Error[] $coercionErrors */
                     $coercionErrors = $coerced['errors'];
-                    if ($coercionErrors) {
+                    if (! empty($coercionErrors)) {
-                        $messagePrelude = "Variable \"\$$varName\" got invalid value " . Utils::printSafeJson($value) . '; ';
+                        $messagePrelude = sprintf(
+                            'Variable "$%s" got invalid value %s; ',
+                            $varName,
+                            Utils::printSafeJson($value)
+                        );
 
-                        foreach($coercionErrors as $error) {
+                        foreach ($coercionErrors as $error) {
                             $errors[] = new Error(
                                 $messagePrelude . $error->getMessage(),
                                 $error->getNodes(),
@@ -87,17 +104,48 @@ class Values
                 }
             }
         }
+
         return ['errors' => $errors, 'coerced' => $errors ? null : $coercedValues];
     }
 
+    /**
+     * Prepares an object map of argument values given a directive definition
+     * and a AST node which may contain directives. Optionally also accepts a map
+     * of variable values.
+     *
+     * If the directive does not exist on the node, returns undefined.
+     *
+     * @param FragmentSpreadNode|FieldNode|InlineFragmentNode|EnumValueDefinitionNode|FieldDefinitionNode $node
+     * @param mixed[]|null                                                                                $variableValues
+     *
+     * @return mixed[]|null
+     */
+    public static function getDirectiveValues(Directive $directiveDef, $node, $variableValues = null)
+    {
+        if (isset($node->directives) && $node->directives instanceof NodeList) {
+            $directiveNode = Utils::find(
+                $node->directives,
+                function (DirectiveNode $directive) use ($directiveDef) {
+                    return $directive->name->value === $directiveDef->name;
+                }
+            );
+
+            if ($directiveNode) {
+                return self::getArgumentValues($directiveDef, $directiveNode, $variableValues);
+            }
+        }
+
+        return null;
+    }
+
     /**
      * Prepares an object map of argument values given a list of argument
      * definitions and list of argument AST nodes.
      *
      * @param FieldDefinition|Directive $def
-     * @param FieldNode|\GraphQL\Language\AST\DirectiveNode $node
+     * @param FieldNode|DirectiveNode   $node
-     * @param $variableValues
+     * @param mixed[]                   $variableValues
-     * @return array
+     * @return mixed[]
      * @throws Error
      */
     public static function getArgumentValues($def, $node, $variableValues = null)
@@ -105,33 +153,36 @@ class Values
         $argDefs  = $def->args;
         $argNodes = $node->arguments;
 
-        if (!$argDefs || null === $argNodes) {
+        if (empty($argDefs) || $argNodes === null) {
             return [];
         }
 
         $coercedValues = [];
 
         /** @var ArgumentNode[] $argNodeMap */
-        $argNodeMap = $argNodes ? Utils::keyMap($argNodes, function (ArgumentNode $arg) {
+        $argNodeMap = $argNodes ? Utils::keyMap(
+            $argNodes,
+            function (ArgumentNode $arg) {
                 return $arg->name->value;
-        }) : [];
+            }
+        ) : [];
 
         foreach ($argDefs as $argDef) {
             $name         = $argDef->name;
             $argType      = $argDef->getType();
-            $argumentNode = isset($argNodeMap[$name]) ? $argNodeMap[$name] : null;
+            $argumentNode = $argNodeMap[$name] ?? null;
 
-            if (!$argumentNode) {
+            if (! $argumentNode) {
                 if ($argDef->defaultValueExists()) {
                     $coercedValues[$name] = $argDef->defaultValue;
-                } else if ($argType instanceof NonNull) {
+                } elseif ($argType instanceof NonNull) {
                     throw new Error(
                         'Argument "' . $name . '" of required type ' .
                         '"' . Utils::printSafe($argType) . '" was not provided.',
                         [$node]
                     );
                 }
-            } else if ($argumentNode->value instanceof VariableNode) {
+            } elseif ($argumentNode->value instanceof VariableNode) {
                 $variableName = $argumentNode->value->name->value;
 
                 if ($variableValues && array_key_exists($variableName, $variableValues)) {
@@ -139,14 +190,14 @@ class Values
                     // This assumes that this query has been validated and the variable
                     // usage here is of the correct type.
                     $coercedValues[$name] = $variableValues[$variableName];
-                } else if ($argDef->defaultValueExists()) {
+                } elseif ($argDef->defaultValueExists()) {
                     $coercedValues[$name] = $argDef->defaultValue;
-                } else if ($argType instanceof NonNull) {
+                } elseif ($argType instanceof NonNull) {
                     throw new Error(
                         'Argument "' . $name . '" of required type "' . Utils::printSafe($argType) . '" was ' .
                         'provided the variable "$' . $variableName . '" which was not provided ' .
                         'a runtime value.',
-                        [ $argumentNode->value ]
+                        [$argumentNode->value]
                     );
                 }
             } else {
@@ -158,49 +209,22 @@ class Values
                     // continue with an invalid argument value.
                     throw new Error(
                         'Argument "' . $name . '" has invalid value ' . Printer::doPrint($valueNode) . '.',
-                        [ $argumentNode->value ]
+                        [$argumentNode->value]
                     );
                 }
                 $coercedValues[$name] = $coercedValue;
             }
         }
+
         return $coercedValues;
     }
 
-    /**
-     * Prepares an object map of argument values given a directive definition
-     * and a AST node which may contain directives. Optionally also accepts a map
-     * of variable values.
-     *
-     * If the directive does not exist on the node, returns undefined.
-     *
-     * @param Directive $directiveDef
-     * @param FragmentSpreadNode | FieldNode | InlineFragmentNode | EnumValueDefinitionNode | FieldDefinitionNode $node
-     * @param array|null $variableValues
-     *
-     * @return array|null
-     */
-    public static function getDirectiveValues(Directive $directiveDef, $node, $variableValues = null)
-    {
-        if (isset($node->directives) && $node->directives instanceof NodeList) {
-            $directiveNode = Utils::find($node->directives, function(DirectiveNode $directive) use ($directiveDef) {
-                return $directive->name->value === $directiveDef->name;
-            });
-
-            if ($directiveNode) {
-                return self::getArgumentValues($directiveDef, $directiveNode, $variableValues);
-            }
-        }
-        return null;
-    }
-
     /**
      * @deprecated as of 8.0 (Moved to \GraphQL\Utils\AST::valueFromAST)
      *
-     * @param $valueNode
+     * @param ValueNode $valueNode
-     * @param InputType $type
      * @param null      $variables
-     * @return array|null|\stdClass
+     * @return mixed[]|null|\stdClass
      */
     public static function valueFromAST($valueNode, InputType $type, $variables = null)
     {
@@ -209,15 +233,19 @@ class Values
 
     /**
      * @deprecated as of 0.12 (Use coerceValue() directly for richer information)
-     * @param $value
+     * @param mixed[] $value
-     * @param InputType $type
+     * @return string[]
-     * @return array
      */
     public static function isValidPHPValue($value, InputType $type)
     {
         $errors = Value::coerceValue($value, $type)['errors'];
+
         return $errors
-            ? array_map(function(/*\Throwable */$error) { return $error->getMessage(); }, $errors)
+            ? array_map(
-            : [];
+                function (Throwable $error) {
+                    return $error->getMessage();
+                },
+                $errors
+            ) : [];
     }
 }

src/Server/Helper.php

@@ -189,7 +189,7 @@ class Helper
      * @api
      * @param ServerConfig $config
      * @param OperationParams[] $operations
-     * @return ExecutionResult[]|Promise
+     * @return ExecutionResult|ExecutionResult[]|Promise
      */
     public function executeBatch(ServerConfig $config, array $operations)
     {

src/Utils/AST.php

@@ -282,7 +282,7 @@ class AST
      * @api
      * @param $valueNode
      * @param InputType $type
-     * @param null $variables
+     * @param mixed[]|null $variables
      * @return array|null|\stdClass
      * @throws \Exception
      */

src/Utils/Utils.php

@@ -59,7 +59,7 @@ class Utils
     /**
      * @param array|Traversable $traversable
      * @param callable $predicate
-     * @return null
+     * @return mixed|null
      */
     public static function find($traversable, callable $predicate)
     {