Improved flexibility of error handling

src/Executor/ExecutionResult.php

@@ -17,7 +17,7 @@ class ExecutionResult implements \JsonSerializable
     public $errors;
     
     /**
-     * @var array[]
+     * @var array
      */
     public $extensions;
 
@@ -26,6 +26,11 @@ class ExecutionResult implements \JsonSerializable
      */
     private $errorFormatter;
 
+    /**
+     * @var callable
+     */
+    private $errorsHandler;
+
     /**
      * @param array $data
      * @param array $errors
@@ -39,6 +44,18 @@ class ExecutionResult implements \JsonSerializable
     }
 
     /**
+     * Define custom error formatting (must conform to http://facebook.github.io/graphql/#sec-Errors)
+     *
+     * Expected signature is: function (GraphQL\Error\Error $error): array
+     *
+     * Default formatter is "GraphQL\Error\FormattedError::createFromException"
+     *
+     * Expected returned value must be an array:
+     * array(
+     *    'message' => 'errorMessage',
+     *    // ... other keys
+     * );
+     *
      * @param callable $errorFormatter
      * @return $this
      */
@@ -49,6 +66,30 @@ class ExecutionResult implements \JsonSerializable
     }
 
     /**
+     * Define custom logic for error handling (filtering, logging, etc).
+     *
+     * Expected handler signature is: function (array $errors, callable $formatter): array
+     *
+     * Default handler is:
+     * function (array $errors, callable $formatter) {
+     *     return array_map($formatter, $errors);
+     * }
+     *
+     * @param callable $handler
+     * @return $this
+     */
+    public function setErrorsHandler(callable $handler)
+    {
+        $this->errorsHandler = $handler;
+        return $this;
+    }
+
+    /**
+     * Converts GraphQL result to array using provided errors handler and formatter.
+     *
+     * Default error formatter is GraphQL\Error\FormattedError::createFromException
+     * Default error handler will simply return all errors formatted. No errors are filtered.
+     *
      * @param bool|int $debug
      * @return array
      */
@@ -68,7 +109,12 @@ class ExecutionResult implements \JsonSerializable
             } else {
                 $errorFormatter = $this->errorFormatter;
             }
-            $result['errors'] = array_map($errorFormatter, $this->errors);
+
+            $errorsHandler = $this->errorsHandler ?: function(array $errors, callable $formatter) {
+                return array_map($formatter, $errors);
+            };
+
+            $result['errors'] = $errorsHandler($this->errors, $errorFormatter);
         }
 
         if (null !== $this->data) {
@@ -82,6 +128,11 @@ class ExecutionResult implements \JsonSerializable
         return $result;
     }
 
+    /**
+     * Part of \JsonSerializable interface
+     *
+     * @return array
+     */
     public function jsonSerialize()
     {
         return $this->toArray();