Various tools for better error reporting / formatting

src/Error/FormattedError.php

@@ -2,7 +2,15 @@
 namespace GraphQL\Error;
 
 use GraphQL\Language\SourceLocation;
+use GraphQL\Type\Definition\Type;
+use GraphQL\Type\Definition\WrappingType;
+use GraphQL\Utils;
 
+/**
+ * Class FormattedError
+ * @todo move this class to Utils/ErrorUtils
+ * @package GraphQL\Error
+ */
 class FormattedError
 {
     /**
@@ -23,4 +31,101 @@ class FormattedError
 
         return $formatted;
     }
+
+    /**
+     * @param \ErrorException $e
+     * @return array
+     */
+    public static function createFromPHPError(\ErrorException $e)
+    {
+        return [
+            'message' => $e->getMessage(),
+            'severity' => $e->getSeverity(),
+            'trace' => self::toSafeTrace($e->getTrace())
+        ];
+    }
+
+    /**
+     * @param \Exception $e
+     * @return array
+     */
+    public static function createFromException(\Exception $e)
+    {
+        return [
+            'message' => $e->getMessage(),
+            'trace' => self::toSafeTrace($e->getTrace())
+        ];
+    }
+
+    /**
+     * Converts error trace to serializable array
+     *
+     * @param array $trace
+     * @return array
+     */
+    private static function toSafeTrace(array $trace)
+    {
+        // Remove invariant entries as they don't provide much value:
+        if (
+            isset($trace[0]['function']) && isset($trace[0]['class']) &&
+            ('GraphQL\Utils::invariant' === $trace[0]['class'].'::'.$trace[0]['function'])) {
+            array_shift($trace);
+        }
+
+        return array_map(function($err) {
+            $safeErr = array_intersect_key($err, ['file' => true, 'line' => true]);
+
+            if (isset($err['function'])) {
+                $func = $err['function'];
+                $args = !empty($err['args']) ? array_map([__CLASS__, 'printVar'], $err['args']) : [];
+                $funcStr = $func . '(' . implode(", ", $args) . ')';
+
+                if (isset($err['class'])) {
+                    $safeErr['call'] = $err['class'] . '::' . $funcStr;
+                } else {
+                    $safeErr['function'] = $funcStr;
+                }
+            }
+
+            return $safeErr;
+        }, $trace);
+    }
+
+    /**
+     * @param $var
+     * @return string
+     */
+    public static function printVar($var)
+    {
+        if ($var instanceof Type) {
+            // FIXME: Replace with schema printer call
+            if ($var instanceof WrappingType) {
+                $var = $var->getWrappedType(true);
+            }
+            return 'GraphQLType: ' . $var->name;
+        }
+
+        if (is_object($var)) {
+            return 'instance of ' . get_class($var) . ($var instanceof \Countable ? '(' . count($var) . ')' : '');
+        }
+        if (is_array($var)) {
+            return 'array(' . count($var) . ')';
+        }
+        if ('' === $var) {
+            return '(empty string)';
+        }
+        if (is_string($var)) {
+            return "'" . addcslashes($var, "'") . "'";
+        }
+        if (is_bool($var)) {
+            return $var ? 'true' : 'false';
+        }
+        if (is_scalar($var)) {
+            return $var;
+        }
+        if (null === $var) {
+            return 'null';
+        }
+        return gettype($var);
+    }
 }

src/Error/InvariantViolation.php

@@ -0,0 +1,15 @@
+<?php
+namespace GraphQL\Error;
+
+/**
+ * Class InvariantVoilation
+ *
+ * Note:
+ * This exception should not inherit base Error exception as it is raised when there is an error somewhere in
+ * user-land code
+ *
+ * @package GraphQL\Error
+ */
+class InvariantViolation extends \LogicException
+{
+}

src/Type/Definition/Config.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Utils;
 
 /**
@@ -184,7 +185,7 @@ class Config
                     }
                 }
             } else {
-                throw new \Exception('Error in "'.$typeName.'" type definition: ' . "unexpected definition: " . print_r($def, true));
+                throw new InvariantViolation('Error in "'.$typeName.'" type definition: ' . "unexpected definition: " . print_r($def, true));
             }
         } else {
             Utils::invariant(is_int($def), 'Error in "'.$typeName.'" type definition: ' . "Definition for '$pathStr' is expected to be single integer value");
@@ -250,7 +251,7 @@ class Config
                     );
                     break;
                 default:
-                    throw new \Exception("Unexpected validation rule: " . $def);
+                    throw new InvariantViolation("Unexpected validation rule: " . $def);
             }
         }
     }

src/Utils.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\WrappingType;
 use GraphQL\Utils\SchemaUtils;
@@ -201,7 +202,7 @@ class Utils
                 array_shift($args);
                 $message = call_user_func_array('sprintf', $args);
             }
-            throw new \Exception($message);
+            throw new InvariantViolation($message);
         }
     }