Schema validation + tests (#148)

docs/type-system/enum-types.md

@@ -64,19 +64,6 @@ $episodeEnum = new EnumType([
 
 which is equivalent of:
 ```php
-$episodeEnum = new EnumType([
-    'name' => 'Episode',
-    'description' => 'One of the films in the Star Wars Trilogy',
-    'values' => [
-        'NEWHOPE' => 'NEWHOPE', 
-        'EMPIRE' => 'EMPIRE', 
-        'JEDI' => 'JEDI'
-    ]
-]);
-```
-
-which is in turn equivalent of:
-```php
 $episodeEnum = new EnumType([
     'name' => 'Episode',
     'description' => 'One of the films in the Star Wars Trilogy',

src/Error/Warning.php

@@ -14,6 +14,13 @@ final class Warning
 
     static $warned = [];
 
+    static private $warningHandler;
+
+    public static function setWarningHandler(callable $warningHandler = null)
+    {
+        self::$warningHandler = $warningHandler;
+    }
+
     static function suppress($suppress = true)
     {
         if (true === $suppress) {
@@ -40,7 +47,10 @@ final class Warning
 
     static function warnOnce($errorMessage, $warningId)
     {
-        if ((self::$enableWarnings & $warningId) > 0 && !isset(self::$warned[$warningId])) {
+        if (self::$warningHandler) {
+            $fn = self::$warningHandler;
+            $fn($errorMessage, $warningId);
+        } else if ((self::$enableWarnings & $warningId) > 0 && !isset(self::$warned[$warningId])) {
             self::$warned[$warningId] = true;
             trigger_error($errorMessage, E_USER_WARNING);
         }
@@ -48,7 +58,10 @@ final class Warning
 
     static function warn($errorMessage, $warningId)
     {
-        if ((self::$enableWarnings & $warningId) > 0) {
+        if (self::$warningHandler) {
+            $fn = self::$warningHandler;
+            $fn($errorMessage, $warningId);
+        } else if ((self::$enableWarnings & $warningId) > 0) {
             trigger_error($errorMessage, E_USER_WARNING);
         }
     }

src/Type/Definition/CustomScalarType.php

@@ -1,6 +1,8 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Utils\Utils;
+
 /**
  * Class CustomScalarType
  * @package GraphQL\Type\Definition
@@ -38,7 +40,11 @@ class CustomScalarType extends ScalarType
      */
     public function parseValue($value)
     {
+        if (isset($this->config['parseValue'])) {
             return call_user_func($this->config['parseValue'], $value);
+        } else {
+            return null;
+        }
     }
 
     /**
@@ -47,6 +53,29 @@ class CustomScalarType extends ScalarType
      */
     public function parseLiteral(/* GraphQL\Language\AST\ValueNode */ $valueNode)
     {
+        if (isset($this->config['parseLiteral'])) {
             return call_user_func($this->config['parseLiteral'], $valueNode);
+        } else {
+            return null;
+        }
+    }
+
+    public function assertValid()
+    {
+        parent::assertValid();
+
+        Utils::invariant(
+            isset($this->config['serialize']) && is_callable($this->config['serialize']),
+            "{$this->name} must provide \"serialize\" function. If this custom Scalar " .
+            'is also used as an input type, ensure "parseValue" and "parseLiteral" ' .
+            'functions are also provided.'
+        );
+        if (isset($this->config['parseValue']) || isset($this->config['parseLiteral'])) {
+            Utils::invariant(
+                isset($this->config['parseValue']) && isset($this->config['parseLiteral']) &&
+                is_callable($this->config['parseValue']) && is_callable($this->config['parseLiteral']),
+                "{$this->name} must provide both \"parseValue\" and \"parseLiteral\" functions."
+            );
+        }
     }
 }

src/Type/Definition/EnumType.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Language\AST\EnumValueNode;
 use GraphQL\Utils\MixedStore;
 use GraphQL\Utils\Utils;
@@ -26,6 +27,11 @@ class EnumType extends Type implements InputType, OutputType, LeafType
      */
     private $nameLookup;
 
+    /**
+     * @var array
+     */
+    public $config;
+
     public function __construct($config)
     {
         if (!isset($config['name'])) {
@@ -47,21 +53,7 @@ class EnumType extends Type implements InputType, OutputType, LeafType
 
         $this->name = $config['name'];
         $this->description = isset($config['description']) ? $config['description'] : null;
-        $this->values = [];
+        $this->config = $config;
-
-        if (!empty($config['values'])) {
-            foreach ($config['values'] as $name => $value) {
-                if (!is_array($value)) {
-                    if (is_string($name)) {
-                        $value = ['name' => $name, 'value' => $value];
-                    } else if (is_int($name) && is_string($value)) {
-                        $value = ['name' => $value, 'value' => $value];
-                    }
-                }
-                // value will be equal to name only if 'value'  is not set in definition
-                $this->values[] = new EnumValueDefinition($value + ['name' => $name, 'value' => $name]);
-            }
-        }
     }
 
     /**
@@ -69,6 +61,33 @@ class EnumType extends Type implements InputType, OutputType, LeafType
      */
     public function getValues()
     {
+        if ($this->values === null) {
+            $this->values = [];
+            $config = $this->config;
+
+            if (isset($config['values'])) {
+                if (!is_array($config['values'])) {
+                    throw new InvariantViolation("{$this->name} values must be an array");
+                }
+                foreach ($config['values'] as $name => $value) {
+                    if (is_string($name)) {
+                        if (!is_array($value)) {
+                            throw new InvariantViolation(
+                                "{$this->name}.$name must refer to an associative array with a " .
+                                '"value" key representing an internal value but got: ' . Utils::printSafe($value)
+                            );
+                        }
+                        $value += ['name' => $name, 'value' => $name];
+                    } else if (is_int($name) && is_string($value)) {
+                        $value = ['name' => $value, 'value' => $value];
+                    } else {
+                        throw new InvariantViolation("{$this->name} values must be an array with value names as keys.");
+                    }
+                    $this->values[] = new EnumValueDefinition($value);
+                }
+            }
+        }
+
         return $this->values;
     }
 
@@ -168,4 +187,42 @@ class EnumType extends Type implements InputType, OutputType, LeafType
         }
         return $this->nameLookup;
     }
+
+    /**
+     * @throws InvariantViolation
+     */
+    public function assertValid()
+    {
+        parent::assertValid();
+
+        Utils::invariant(
+            isset($this->config['values']),
+            "{$this->name} values must be an array."
+        );
+
+        $values = $this->getValues();
+
+        Utils::invariant(
+            !empty($values),
+            "{$this->name} values must be not empty."
+        );
+        foreach ($values as $value) {
+            try {
+                Utils::assertValidName($value->name);
+            } catch (InvariantViolation $e) {
+                throw new InvariantViolation(
+                    "{$this->name} has value with invalid name: " .
+                    Utils::printSafe($value->name) . " ({$e->getMessage()})"
+                );
+            }
+            Utils::invariant(
+                !in_array($value->name, ['true', 'false', 'null']),
+                "{$this->name}: \"{$value->name}\" can not be used as an Enum value."
+            );
+            Utils::invariant(
+                !isset($value->config['isDeprecated']),
+                "{$this->name}.{$value->name} should provide \"deprecationReason\" instead of \"isDeprecated\"."
+            );
+        }
+    }
 }

src/Type/Definition/EnumValueDefinition.php

@@ -28,9 +28,19 @@ class EnumValueDefinition
      */
     public $description;
 
+    /**
+     * @var array
+     */
+    public $config;
+
     public function __construct(array $config)
     {
-        Utils::assign($this, $config);
+        $this->name = isset($config['name']) ? $config['name'] : null;
+        $this->value = isset($config['value']) ? $config['value'] : null;
+        $this->deprecationReason = isset($config['deprecationReason']) ? $config['deprecationReason'] : null;
+        $this->description = isset($config['description']) ? $config['description'] : null;
+
+        $this->config = $config;
     }
 
     /**

src/Type/Definition/FieldArgument.php

@@ -1,6 +1,9 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
+use GraphQL\Utils\Utils;
+
 
 /**
  * Class FieldArgument
@@ -105,4 +108,29 @@ class FieldArgument
     {
         return $this->defaultValueExists;
     }
+
+    public function assertValid(FieldDefinition $parentField, Type $parentType)
+    {
+        try {
+            Utils::assertValidName($this->name);
+        } catch (InvariantViolation $e) {
+            throw new InvariantViolation(
+                "{$parentType->name}.{$parentField->name}({$this->name}:) {$e->getMessage()}")
+            ;
+        }
+        $type = $this->type;
+        if ($type instanceof WrappingType) {
+            $type = $type->getWrappedType(true);
+        }
+        Utils::invariant(
+            $type instanceof InputType,
+            "{$parentType->name}.{$parentField->name}({$this->name}): argument type must be " .
+            "Input Type but got: " . Utils::printSafe($this->type)
+        );
+        Utils::invariant(
+            $this->description === null || is_string($this->description),
+            "{$parentType->name}.{$parentField->name}({$this->name}): argument description type must be " .
+            "string but got: " . Utils::printSafe($this->description)
+        );
+    }
 }

src/Type/Definition/FieldDefinition.php

@@ -89,28 +89,72 @@ class FieldDefinition
         ]);
     }
 
-    /**
+    public static function defineFieldMap(Type $type, $fields)
-     * @param array|Config $fields
-     * @param string $parentTypeName
-     * @return array
-     */
-    public static function createMap(array $fields, $parentTypeName = null)
     {
+        if (is_callable($fields)) {
+            $fields = $fields();
+        }
+        if (!is_array($fields)) {
+            throw new InvariantViolation(
+                "{$type->name} fields must be an array or a callable which returns such an array."
+            );
+        }
         $map = [];
         foreach ($fields as $name => $field) {
             if (is_array($field)) {
                 if (!isset($field['name']) && is_string($name)) {
                     $field['name'] = $name;
                 }
-                $fieldDef = self::create($field, $parentTypeName);
+                if (isset($field['args']) && !is_array($field['args'])) {
+                    throw new InvariantViolation(
+                        "{$type->name}.{$name} args must be an array."
+                    );
+                }
+                $fieldDef = self::create($field);
+            } else if ($field instanceof FieldDefinition) {
+                $fieldDef = $field;
+            } else {
+                if (is_string($name) && $field) {
+                    $fieldDef = self::create(['name' => $name, 'type' => $field]);
+                } else {
+                    throw new InvariantViolation(
+                        "{$type->name}.$name field config must be an array, but got: " . Utils::printSafe($field)
+                    );
+                }
+            }
+            $map[$fieldDef->name] = $fieldDef;
+        }
+        return $map;
+    }
+
+    /**
+     * @param array|Config $fields
+     * @param string $parentTypeName
+     * @deprecated
+     * @return array
+     */
+    public static function createMap(array $fields, $parentTypeName = null)
+    {
+        trigger_error(
+            __METHOD__ . ' is deprecated, use ' . __CLASS__ . '::defineFieldMap() instead',
+            E_USER_DEPRECATED
+        );
+
+        $map = [];
+        foreach ($fields as $name => $field) {
+            if (is_array($field)) {
+                if (!isset($field['name']) && is_string($name)) {
+                    $field['name'] = $name;
+                }
+                $fieldDef = self::create($field);
             } else if ($field instanceof FieldDefinition) {
                 $fieldDef = $field;
             } else {
                 if (is_string($name)) {
-                    $fieldDef = self::create(['name' => $name, 'type' => $field], $parentTypeName);
+                    $fieldDef = self::create(['name' => $name, 'type' => $field]);
                 } else {
                     throw new InvariantViolation(
-                        "Unexpected field definition for type $parentTypeName at key $name: " . Utils::printSafe($field)
+                        "Unexpected field definition for type $parentTypeName at field $name: " . Utils::printSafe($field)
                     );
                 }
             }
@@ -195,6 +239,37 @@ class FieldDefinition
         return $this->complexityFn;
     }
 
+    /**
+     * @param Type $parentType
+     * @throws InvariantViolation
+     */
+    public function assertValid(Type $parentType)
+    {
+        try {
+            Utils::assertValidName($this->name);
+        } catch (InvariantViolation $e) {
+            throw new InvariantViolation("{$parentType->name}.{$this->name}: {$e->getMessage()}");
+        }
+        Utils::invariant(
+            !isset($this->config['isDeprecated']),
+            "{$parentType->name}.{$this->name} should provide \"deprecationReason\" instead of \"isDeprecated\"."
+        );
+
+        $type = $this->type;
+        if ($type instanceof WrappingType) {
+            $type = $type->getWrappedType(true);
+        }
+        Utils::invariant(
+            $type instanceof OutputType,
+            "{$parentType->name}.{$this->name} field type must be Output Type but got: " . Utils::printSafe($this->type)
+        );
+        Utils::invariant(
+            $this->resolveFn === null || is_callable($this->resolveFn),
+            "{$parentType->name}.{$this->name} field resolver must be a function if provided, but got: %s",
+            Utils::printSafe($this->resolveFn)
+        );
+    }
+
     /**
      * @param $childrenComplexity
      * @return mixed

src/Type/Definition/InputObjectField.php

@@ -27,6 +27,11 @@ class InputObjectField
      */
     public $type;
 
+    /**
+     * @var array
+     */
+    public $config;
+
     /**
      * Helps to differentiate when `defaultValue` is `null` and when it was not even set initially
      *
@@ -52,6 +57,7 @@ class InputObjectField
                     $this->{$k} = $v;
             }
         }
+        $this->config = $opts;
     }
 
     /**

src/Type/Definition/InputObjectType.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Utils\Utils;
 
 /**
@@ -56,6 +57,13 @@ class InputObjectType extends Type implements InputType
             $this->fields = [];
             $fields = isset($this->config['fields']) ? $this->config['fields'] : [];
             $fields = is_callable($fields) ? call_user_func($fields) : $fields;
+
+            if (!is_array($fields)) {
+                throw new InvariantViolation(
+                    "{$this->name} fields must be an array or a callable which returns such an array."
+                );
+            }
+
             foreach ($fields as $name => $field) {
                 if ($field instanceof Type) {
                     $field = ['type' => $field];
@@ -81,4 +89,41 @@ class InputObjectType extends Type implements InputType
         Utils::invariant(isset($this->fields[$name]), "Field '%s' is not defined for type '%s'", $name, $this->name);
         return $this->fields[$name];
     }
+
+    /**
+     * @throws InvariantViolation
+     */
+    public function assertValid()
+    {
+        parent::assertValid();
+
+        $fields = $this->getFields();
+
+        Utils::invariant(
+            !empty($fields),
+            "{$this->name} fields must not be empty"
+        );
+
+        foreach ($fields as $field) {
+            try {
+                Utils::assertValidName($field->name);
+            } catch (InvariantViolation $e) {
+                throw new InvariantViolation("{$this->name}.{$field->name}: {$e->getMessage()}");
+            }
+
+            $fieldType = $field->type;
+            if ($fieldType instanceof WrappingType) {
+                $fieldType = $fieldType->getWrappedType(true);
+            }
+            Utils::invariant(
+                $fieldType instanceof InputType,
+                "{$this->name}.{$field->name} field type must be Input Type but got: %s.",
+                Utils::printSafe($field->type)
+            );
+            Utils::invariant(
+                !isset($field->config['resolve']),
+                "{$this->name}.{$field->name} field type has a resolve property, but Input Types cannot define resolvers."
+            );
+        }
+    }
 }

src/Type/Definition/InterfaceType.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Utils\Utils;
 
 /**
@@ -57,10 +58,8 @@ class InterfaceType extends Type implements AbstractType, OutputType, CompositeT
     public function getFields()
     {
         if (null === $this->fields) {
-            $this->fields = [];
             $fields = isset($this->config['fields']) ? $this->config['fields'] : [];
-            $fields = is_callable($fields) ? call_user_func($fields) : $fields;
+            $this->fields = FieldDefinition::defineFieldMap($this, $fields);
-            $this->fields = FieldDefinition::createMap($fields, $this->name);
         }
         return $this->fields;
     }
@@ -95,4 +94,31 @@ class InterfaceType extends Type implements AbstractType, OutputType, CompositeT
         }
         return null;
     }
+
+    /**
+     * @throws InvariantViolation
+     */
+    public function assertValid()
+    {
+        parent::assertValid();
+
+        $fields = $this->getFields();
+
+        Utils::invariant(
+            !isset($this->config['resolveType']) || is_callable($this->config['resolveType']),
+            "{$this->name} must provide \"resolveType\" as a function."
+        );
+
+        Utils::invariant(
+            !empty($fields),
+            "{$this->name} fields must not be empty"
+        );
+
+        foreach ($fields as $field) {
+            $field->assertValid($this);
+            foreach ($field->args as $arg) {
+                $arg->assertValid($field, $this);
+            }
+        }
+    }
 }

src/Type/Definition/ListOfType.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Utils\Utils;
 
 /**
@@ -19,11 +20,11 @@ class ListOfType extends Type implements WrappingType, OutputType, InputType
      */
     public function __construct($type)
     {
-        Utils::invariant(
+        if (!$type instanceof Type && !is_callable($type)) {
-            $type instanceof Type || is_callable($type),
+            throw new InvariantViolation(
-            'Expecting instance of GraphQL\Type\Definition\Type or callable returning instance of that class'
+                'Can only create List of a GraphQLType but got: ' . Utils::printSafe($type)
             );
-
+        }
         $this->ofType = $type;
     }
 

src/Type/Definition/NonNull.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Utils\Utils;
 
 /**
@@ -20,10 +21,16 @@ class NonNull extends Type implements WrappingType, OutputType, InputType
      */
     public function __construct($type)
     {
-        Utils::invariant(
+        if (!$type instanceof Type && !is_callable($type)) {
-            $type instanceof Type || is_callable($type),
+            throw new InvariantViolation(
-            'Expecting instance of GraphQL\Type\Definition\Type or callable returning instance of that class'
+                'Can only create NonNull of a Nullable GraphQLType but got: ' . Utils::printSafe($type)
             );
+        }
+        if ($type instanceof NonNull) {
+            throw new InvariantViolation(
+                'Can only create NonNull of a Nullable GraphQLType but got: ' . Utils::printSafe($type)
+            );
+        }
         Utils::invariant(
             !($type instanceof NonNull),
             'Cannot nest NonNull inside NonNull'

src/Type/Definition/ObjectType.php

@@ -1,6 +1,6 @@
 <?php
 namespace GraphQL\Type\Definition;
-use GraphQL\Error\Error;
+
 use GraphQL\Error\InvariantViolation;
 use GraphQL\Utils\Utils;
 
@@ -60,7 +60,7 @@ class ObjectType extends Type implements OutputType, CompositeType
     /**
      * @var array
      */
-    private $interfaceMap = [];
+    private $interfaceMap;
 
     /**
      * Keeping reference of config for late bindings and custom app-level metadata
@@ -111,13 +111,13 @@ class ObjectType extends Type implements OutputType, CompositeType
 
     /**
      * @return FieldDefinition[]
+     * @throws InvariantViolation
      */
     public function getFields()
     {
         if (null === $this->fields) {
             $fields = isset($this->config['fields']) ? $this->config['fields'] : [];
-            $fields = is_callable($fields) ? call_user_func($fields) : $fields;
+            $this->fields = FieldDefinition::defineFieldMap($this, $fields);
-            $this->fields = FieldDefinition::createMap($fields, $this->name);
         }
         return $this->fields;
     }
@@ -132,9 +132,7 @@ class ObjectType extends Type implements OutputType, CompositeType
         if (null === $this->fields) {
             $this->getFields();
         }
-        if (!isset($this->fields[$name])) {
+        Utils::invariant(isset($this->fields[$name]), 'Field "%s" is not defined for type "%s"', $name, $this->name);
-            throw new Error(sprintf("Field '%s' is not defined for type '%s'", $name, $this->name));
-        }
         return $this->fields[$name];
     }
 
@@ -147,11 +145,21 @@ class ObjectType extends Type implements OutputType, CompositeType
             $interfaces = isset($this->config['interfaces']) ? $this->config['interfaces'] : [];
             $interfaces = is_callable($interfaces) ? call_user_func($interfaces) : $interfaces;
 
+            if (!is_array($interfaces)) {
+                throw new InvariantViolation(
+                    "{$this->name} interfaces must be an Array or a callable which returns an Array."
+                );
+            }
+
             $this->interfaces = [];
             foreach ($interfaces as $iface) {
                 $iface = Type::resolve($iface);
                 if (!$iface instanceof InterfaceType) {
-                    throw new InvariantViolation(sprintf('Expecting interface type, got %s', Utils::printSafe($iface)));
+                    throw new InvariantViolation(sprintf(
+                        '%s may only implement Interface types, it cannot implement %s',
+                        $this->name,
+                        Utils::printSafe($iface)
+                    ));
                 }
                 // TODO: return interfaceMap vs interfaces. Possibly breaking change?
                 $this->interfaces[] = $iface;
@@ -161,6 +169,17 @@ class ObjectType extends Type implements OutputType, CompositeType
         return $this->interfaces;
     }
 
+    private function getInterfaceMap()
+    {
+        if (!$this->interfaceMap) {
+            $this->interfaceMap = [];
+            foreach ($this->getInterfaces() as $interface) {
+                $this->interfaceMap[$interface->name] = $interface;
+            }
+        }
+        return $this->interfaceMap;
+    }
+
     /**
      * @param InterfaceType $iface
      * @return bool
@@ -182,4 +201,61 @@ class ObjectType extends Type implements OutputType, CompositeType
     {
         return isset($this->config['isTypeOf']) ? call_user_func($this->config['isTypeOf'], $value, $context, $info) : null;
     }
+
+    /**
+     * Validates type config and throws if one of type options is invalid.
+     * Note: this method is shallow, it won't validate object fields and their arguments.
+     *
+     * @throws InvariantViolation
+     */
+    public function assertValid()
+    {
+        parent::assertValid();
+
+        Utils::invariant(
+            null === $this->description || is_string($this->description),
+            "{$this->name} description must be string if set, but it is: " . Utils::printSafe($this->description)
+        );
+
+        Utils::invariant(
+            !isset($this->config['isTypeOf']) || is_callable($this->config['isTypeOf']),
+            "{$this->name} must provide 'isTypeOf' as a function"
+        );
+
+        // getFields() and getInterfaceMap() will do structural validation
+        $fields = $this->getFields();
+        Utils::invariant(
+            !empty($fields),
+            "{$this->name} fields must not be empty"
+        );
+        foreach ($fields as $field) {
+            $field->assertValid($this);
+            foreach ($field->args as $arg) {
+                $arg->assertValid($field, $this);
+            }
+        }
+
+        $implemented = [];
+        foreach ($this->getInterfaces() as $iface) {
+            Utils::invariant(
+                $iface instanceof InterfaceType,
+                "{$this->name} may only implement Interface types, it cannot implement: %s.",
+                Utils::printSafe($iface)
+            );
+            Utils::invariant(
+                !isset($implemented[$iface->name]),
+                "{$this->name} may declare it implements {$iface->name} only once."
+            );
+            $implemented[$iface->name] = true;
+            if (!isset($iface->config['resolveType'])) {
+                Utils::invariant(
+                    isset($this->config['isTypeOf']),
+                    "Interface Type {$iface->name} does not provide a \"resolveType\" " .
+                    "function and implementing Type {$this->name} does not provide a " .
+                    '"isTypeOf" function. There is no way to resolve this implementing ' .
+                    'type during execution.'
+                );
+            }
+        }
+    }
 }

src/Type/Definition/Type.php

@@ -237,6 +237,13 @@ abstract class Type implements \JsonSerializable
         return null;
     }
 
+    /**
+     * @throws InvariantViolation
+     */
+    public function assertValid()
+    {
+    }
+
     /**
      * @return string
      */

src/Type/Definition/UnionType.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Utils\Utils;
 
 /**
@@ -68,17 +69,19 @@ class UnionType extends Type implements AbstractType, OutputType, CompositeType
     public function getTypes()
     {
         if (null === $this->types) {
-            if ($this->config['types'] instanceof \Closure) {
+            if (!isset($this->config['types'])) {
+                $types = null;
+            } else if (is_callable($this->config['types'])) {
                 $types = call_user_func($this->config['types']);
             } else {
                 $types = $this->config['types'];
             }
 
-            Utils::invariant(
+            if (!is_array($types)) {
-                is_array($types),
+                throw new InvariantViolation(
-                'Option "types" of union "%s" is expected to return array of types (or closure returning array of types)',
+                    "{$this->name} types must be an Array or a callable which returns an Array."
-                $this->name
                 );
+            }
 
             $this->types = [];
             foreach ($types as $type) {
@@ -123,4 +126,48 @@ class UnionType extends Type implements AbstractType, OutputType, CompositeType
         }
         return null;
     }
+
+    /**
+     * @throws InvariantViolation
+     */
+    public function assertValid()
+    {
+        parent::assertValid();
+
+        $types = $this->getTypes();
+        Utils::invariant(
+            !empty($types),
+            "{$this->name} types must not be empty"
+        );
+
+        if (isset($this->config['resolveType'])) {
+            Utils::invariant(
+                is_callable($this->config['resolveType']),
+                "{$this->name} must provide \"resolveType\" as a function."
+            );
+        }
+
+        $includedTypeNames = [];
+        foreach ($types as $objType) {
+            Utils::invariant(
+                $objType instanceof ObjectType,
+                "{$this->name} may only contain Object types, it cannot contain: %s.",
+                Utils::printSafe($objType)
+            );
+            Utils::invariant(
+                !isset($includedTypeNames[$objType->name]),
+                "{$this->name} can include {$objType->name} type only once."
+            );
+            $includedTypeNames[$objType->name] = true;
+            if (!isset($this->config['resolveType'])) {
+                Utils::invariant(
+                    isset($objType->config['isTypeOf']) && is_callable($objType->config['isTypeOf']),
+                    "Union type \"{$this->name}\" does not provide a \"resolveType\" " .
+                    "function and possible type \"{$objType->name}\" does not provide an " .
+                    '"isTypeOf" function. There is no way to resolve this possible type ' .
+                    'during execution.'
+                );
+            }
+        }
+    }
 }

src/Type/Schema.php

@@ -390,4 +390,111 @@ class Schema
         }
         return $this->resolvedTypes[$typeName];
     }
+
+
+    /**
+     * @throws InvariantViolation
+     */
+    public function assertValid()
+    {
+        foreach ($this->config->getDirectives() as $index => $directive) {
+            Utils::invariant(
+                $directive instanceof Directive,
+                "Each entry of \"directives\" option of Schema config must be an instance of %s but entry at position %d is %s.",
+                Directive::class,
+                $index,
+                Utils::printSafe($directive)
+            );
+        }
+
+        foreach ($this->getTypeMap() as $name => $type) {
+            $type->assertValid();
+
+            if ($type instanceof AbstractType) {
+                $possibleTypes = $this->getPossibleTypes($type);
+
+                Utils::invariant(
+                    !empty($possibleTypes),
+                    "Could not find possible implementing types for {$type->name} " .
+                    'in schema. Check that schema.types is defined and is an array of ' .
+                    'all possible types in the schema.'
+                );
+
+            } else if ($type instanceof ObjectType) {
+                foreach ($type->getInterfaces() as $iface) {
+                    $this->assertImplementsIntarface($type, $iface);
+                }
+            }
+        }
+    }
+
+    private function assertImplementsIntarface(ObjectType $object, InterfaceType $iface)
+    {
+        $objectFieldMap = $object->getFields();
+        $ifaceFieldMap  = $iface->getFields();
+
+        // Assert each interface field is implemented.
+        foreach ($ifaceFieldMap as $fieldName => $ifaceField) {
+
+            // Assert interface field exists on object.
+            Utils::invariant(
+                isset($objectFieldMap[$fieldName]),
+                "{$iface->name} expects field \"{$fieldName}\" but {$object->name} does not provide it"
+            );
+
+            $objectField = $objectFieldMap[$fieldName];
+
+            // Assert interface field type is satisfied by object field type, by being
+            // a valid subtype. (covariant)
+            Utils::invariant(
+                TypeComparators::isTypeSubTypeOf($this, $objectField->getType(), $ifaceField->getType()),
+                "{$iface->name}.{$fieldName} expects type \"{$ifaceField->getType()}\" " .
+                "but " .
+                "{$object->name}.${fieldName} provides type \"{$objectField->getType()}\""
+            );
+
+            // Assert each interface field arg is implemented.
+            foreach ($ifaceField->args as $ifaceArg) {
+                $argName = $ifaceArg->name;
+
+                /** @var FieldArgument $objectArg */
+                $objectArg = Utils::find($objectField->args, function(FieldArgument $arg) use ($argName) {
+                    return $arg->name === $argName;
+                });
+
+                // Assert interface field arg exists on object field.
+                Utils::invariant(
+                    $objectArg,
+                    "{$iface->name}.{$fieldName} expects argument \"{$argName}\" but ".
+                    "{$object->name}.{$fieldName} does not provide it."
+                );
+
+                // Assert interface field arg type matches object field arg type.
+                // (invariant)
+                Utils::invariant(
+                    TypeComparators::isEqualType($ifaceArg->getType(), $objectArg->getType()),
+                    "{$iface->name}.{$fieldName}({$argName}:) expects type " .
+                    "\"{$ifaceArg->getType()->name}\" but " .
+                    "{$object->name}.{$fieldName}({$argName}:) provides type " .
+                    "\"{$objectArg->getType()->name}\"."
+                );
+
+                // Assert additional arguments must not be required.
+                foreach ($objectField->args as $objectArg) {
+                    $argName = $objectArg->name;
+                    $ifaceArg = Utils::find($ifaceField->args, function(FieldArgument $arg) use ($argName) {
+                        return $arg->name === $argName;
+                    });
+                    if (!$ifaceArg) {
+                        Utils::invariant(
+                            !($objectArg->getType() instanceof NonNull),
+                            "{$object->name}.{$fieldName}({$argName}:) is of required type " .
+                            "\"{$objectArg->getType()}\" but is not also provided by the " .
+                            "interface {$iface->name}.{$fieldName}."
+                        );
+                    }
+                }
+            }
+        }
+    }
 }

src/Type/SchemaConfig.php

@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type;
 
+use GraphQL\Error\InvariantViolation;
 use GraphQL\Type\Descriptor;
 use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\ObjectType;
@@ -203,7 +204,7 @@ class SchemaConfig
      */
     public function getDirectives()
     {
-        return $this->directives;
+        return $this->directives ?: [];
     }
 
     /**

src/Utils/TypeComparators.php

@@ -0,0 +1,137 @@
+<?php
+namespace GraphQL\Utils;
+
+use GraphQL\Type\Schema;
+use GraphQL\Type\Definition\AbstractType;
+use GraphQL\Type\Definition\CompositeType;
+use GraphQL\Type\Definition\ListOfType;
+use GraphQL\Type\Definition\NonNull;
+use GraphQL\Type\Definition\ObjectType;
+use GraphQL\Type\Definition\Type;
+
+class TypeComparators
+{
+    /**
+     * Provided two types, return true if the types are equal (invariant).
+     *
+     * @param Type $typeA
+     * @param Type $typeB
+     * @return bool
+     */
+    public static function isEqualType(Type $typeA, Type $typeB)
+    {
+        // Equivalent types are equal.
+        if ($typeA === $typeB) {
+            return true;
+        }
+
+        // If either type is non-null, the other must also be non-null.
+        if ($typeA instanceof NonNull && $typeB instanceof NonNull) {
+            return self::isEqualType($typeA->getWrappedType(), $typeB->getWrappedType());
+        }
+
+        // If either type is a list, the other must also be a list.
+        if ($typeA instanceof ListOfType && $typeB instanceof ListOfType) {
+            return self::isEqualType($typeA->getWrappedType(), $typeB->getWrappedType());
+        }
+
+        // Otherwise the types are not equal.
+        return false;
+    }
+
+    /**
+     * Provided a type and a super type, return true if the first type is either
+     * equal or a subset of the second super type (covariant).
+     *
+     * @param Schema $schema
+     * @param Type $maybeSubType
+     * @param Type $superType
+     * @return bool
+     */
+    static function isTypeSubTypeOf(Schema $schema, Type $maybeSubType, Type $superType)
+    {
+        // Equivalent type is a valid subtype
+        if ($maybeSubType === $superType) {
+            return true;
+        }
+
+        // If superType is non-null, maybeSubType must also be nullable.
+        if ($superType instanceof NonNull) {
+            if ($maybeSubType instanceof NonNull) {
+                return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType->getWrappedType());
+            }
+            return false;
+        } else if ($maybeSubType instanceof NonNull) {
+            // If superType is nullable, maybeSubType may be non-null.
+            return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType);
+        }
+
+        // If superType type is a list, maybeSubType type must also be a list.
+        if ($superType instanceof ListOfType) {
+            if ($maybeSubType instanceof ListOfType) {
+                return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType->getWrappedType());
+            }
+            return false;
+        } else if ($maybeSubType instanceof ListOfType) {
+            // If superType is not a list, maybeSubType must also be not a list.
+            return false;
+        }
+
+        // If superType type is an abstract type, maybeSubType type may be a currently
+        // possible object type.
+        if (Type::isAbstractType($superType) && $maybeSubType instanceof ObjectType && $schema->isPossibleType($superType, $maybeSubType)) {
+            return true;
+        }
+
+        // Otherwise, the child type is not a valid subtype of the parent type.
+        return false;
+    }
+
+    /**
+     * Provided two composite types, determine if they "overlap". Two composite
+     * types overlap when the Sets of possible concrete types for each intersect.
+     *
+     * This is often used to determine if a fragment of a given type could possibly
+     * be visited in a context of another type.
+     *
+     * This function is commutative.
+     *
+     * @param Schema $schema
+     * @param CompositeType $typeA
+     * @param CompositeType $typeB
+     * @return bool
+     */
+    static function doTypesOverlap(Schema $schema, CompositeType $typeA, CompositeType $typeB)
+    {
+        // Equivalent types overlap
+        if ($typeA === $typeB) {
+            return true;
+        }
+
+        if ($typeA instanceof AbstractType) {
+            if ($typeB instanceof AbstractType) {
+                // If both types are abstract, then determine if there is any intersection
+                // between possible concrete types of each.
+                foreach ($schema->getPossibleTypes($typeA) as $type) {
+                    if ($schema->isPossibleType($typeB, $type)) {
+                        return true;
+                    }
+                }
+                return false;
+            }
+
+            /** @var $typeB ObjectType */
+            // Determine if the latter type is a possible concrete type of the former.
+            return $schema->isPossibleType($typeA, $typeB);
+        }
+
+        if ($typeB instanceof AbstractType) {
+            /** @var $typeA ObjectType */
+            // Determine if the former type is a possible concrete type of the latter.
+            return $schema->isPossibleType($typeB, $typeA);
+        }
+
+        // Otherwise the types do not overlap.
+        return false;
+    }
+}

src/Utils/TypeInfo.php

@@ -7,8 +7,7 @@ use GraphQL\Language\AST\NamedTypeNode;
 use GraphQL\Language\AST\Node;
 use GraphQL\Language\AST\NodeKind;
 use GraphQL\Language\AST\NonNullTypeNode;
-use GraphQL\Schema;
+use GraphQL\Type\Schema;
-use GraphQL\Type\Definition\AbstractType;
 use GraphQL\Type\Definition\CompositeType;
 use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\EnumType;
@@ -32,114 +31,27 @@ use GraphQL\Type\Introspection;
 class TypeInfo
 {
     /**
-     * Provided two types, return true if the types are equal (invariant).
+     * @deprecated moved to GraphQL\Utils\TypeComparators
      */
     public static function isEqualType(Type $typeA, Type $typeB)
     {
-        // Equivalent types are equal.
+        return TypeComparators::isEqualType($typeA, $typeB);
-        if ($typeA === $typeB) {
-            return true;
-        }
-
-        // If either type is non-null, the other must also be non-null.
-        if ($typeA instanceof NonNull && $typeB instanceof NonNull) {
-            return self::isEqualType($typeA->getWrappedType(), $typeB->getWrappedType());
-        }
-
-        // If either type is a list, the other must also be a list.
-        if ($typeA instanceof ListOfType && $typeB instanceof ListOfType) {
-            return self::isEqualType($typeA->getWrappedType(), $typeB->getWrappedType());
-        }
-
-        // Otherwise the types are not equal.
-        return false;
     }
 
     /**
-     * Provided a type and a super type, return true if the first type is either
+     * @deprecated moved to GraphQL\Utils\TypeComparators
-     * equal or a subset of the second super type (covariant).
      */
     static function isTypeSubTypeOf(Schema $schema, Type $maybeSubType, Type $superType)
     {
-        // Equivalent type is a valid subtype
+        return TypeComparators::isTypeSubTypeOf($schema, $maybeSubType, $superType);
-        if ($maybeSubType === $superType) {
-            return true;
     }
 
-        // If superType is non-null, maybeSubType must also be nullable.
-        if ($superType instanceof NonNull) {
-            if ($maybeSubType instanceof NonNull) {
-                return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType->getWrappedType());
-            }
-            return false;
-        } else if ($maybeSubType instanceof NonNull) {
-            // If superType is nullable, maybeSubType may be non-null.
-            return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType);
-        }
-
-        // If superType type is a list, maybeSubType type must also be a list.
-        if ($superType instanceof ListOfType) {
-            if ($maybeSubType instanceof ListOfType) {
-                return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType->getWrappedType());
-            }
-            return false;
-        } else if ($maybeSubType instanceof ListOfType) {
-            // If superType is not a list, maybeSubType must also be not a list.
-            return false;
-        }
-
-        // If superType type is an abstract type, maybeSubType type may be a currently
-        // possible object type.
-        if (Type::isAbstractType($superType) && $maybeSubType instanceof ObjectType && $schema->isPossibleType($superType, $maybeSubType)) {
-            return true;
-        }
-
-        // Otherwise, the child type is not a valid subtype of the parent type.
-        return false;
-    }
-
-
     /**
-     * Provided two composite types, determine if they "overlap". Two composite
+     * @deprecated moved to GraphQL\Utils\TypeComparators
-     * types overlap when the Sets of possible concrete types for each intersect.
-     *
-     * This is often used to determine if a fragment of a given type could possibly
-     * be visited in a context of another type.
-     *
-     * This function is commutative.
      */
     static function doTypesOverlap(Schema $schema, CompositeType $typeA, CompositeType $typeB)
     {
-        // Equivalent types overlap
+        return TypeComparators::doTypesOverlap($schema, $typeA, $typeB);
-        if ($typeA === $typeB) {
-            return true;
-        }
-
-        if ($typeA instanceof AbstractType) {
-            if ($typeB instanceof AbstractType) {
-                // If both types are abstract, then determine if there is any intersection
-                // between possible concrete types of each.
-                foreach ($schema->getPossibleTypes($typeA) as $type) {
-                    if ($schema->isPossibleType($typeB, $type)) {
-                        return true;
-                    }
-                }
-                return false;
-            }
-
-            /** @var $typeB ObjectType */
-            // Determine if the latter type is a possible concrete type of the former.
-            return $schema->isPossibleType($typeA, $typeB);
-        }
-
-        if ($typeB instanceof AbstractType) {
-            /** @var $typeA ObjectType */
-            // Determine if the former type is a possible concrete type of the latter.
-            return $schema->isPossibleType($typeB, $typeA);
-        }
-
-        // Otherwise the types do not overlap.
-        return false;
     }
 
 

src/Utils/Utils.php

@@ -218,7 +218,7 @@ class Utils
      * @param string $message
      * @param mixed $sprintfParam1
      * @param mixed $sprintfParam2 ...
-     * @throws \Exception
+     * @throws InvariantViolation
      */
     public static function invariant($test, $message = '')
     {
@@ -420,7 +420,7 @@ class Utils
     /**
      * @param $name
      * @param bool $isIntrospection
-     * @throws Error
+     * @throws InvariantViolation
      */
     public static function assertValidName($name, $isIntrospection = false)
     {

src/Validator/Rules/VariablesInAllowedPosition.php

@@ -7,6 +7,7 @@ use GraphQL\Language\AST\OperationDefinitionNode;
 use GraphQL\Language\AST\VariableDefinitionNode;
 use GraphQL\Type\Definition\ListOfType;
 use GraphQL\Type\Definition\NonNull;
+use GraphQL\Utils\TypeComparators;
 use GraphQL\Utils\TypeInfo;
 use GraphQL\Validator\ValidationContext;
 
@@ -45,7 +46,7 @@ class VariablesInAllowedPosition
                             $schema = $context->getSchema();
                             $varType = TypeInfo::typeFromAST($schema, $varDef->type);
 
-                            if ($varType && !TypeInfo::isTypeSubTypeOf($schema, $this->effectiveType($varType, $varDef), $type)) {
+                            if ($varType && !TypeComparators::isTypeSubTypeOf($schema, $this->effectiveType($varType, $varDef), $type)) {
                                 $context->reportError(new Error(
                                     self::badVarPosMessage($varName, $varType, $type),
                                     [$varDef, $node]

tests/Executor/LazyInterfaceTest.php

@@ -62,12 +62,12 @@ class LazyInterfaceTest extends \PHPUnit_Framework_TestCase
         if (!$this->lazyInterface) {
             $this->lazyInterface = new InterfaceType([
                 'name' => 'LazyInterface',
+                'fields' => [
+                    'a' => Type::string()
+                ],
                 'resolveType' => function() {
                     return $this->getTestObjectType();
                 },
-                'resolve' => function() {
-                    return [];
-                }
             ]);
         }
 

tests/ServerTest.php

@@ -47,7 +47,7 @@ class ServerTest extends \PHPUnit_Framework_TestCase
 
     public function testSchemaDefinition()
     {
-        $mutationType = $queryType = $subscriptionType = new ObjectType(['name' => 'A', 'fields' => []]);
+        $mutationType = $queryType = $subscriptionType = new ObjectType(['name' => 'A', 'fields' => ['a' => Type::string()]]);
 
         $schema = new Schema([
             'query' => $queryType
@@ -283,7 +283,7 @@ class ServerTest extends \PHPUnit_Framework_TestCase
     public function testValidate()
     {
         $server = Server::create()
-            ->setQueryType(new ObjectType(['name' => 'Q', 'fields' => []]));
+            ->setQueryType(new ObjectType(['name' => 'Q', 'fields' => ['a' => Type::string()]]));
 
         $ast = $server->parse('{q}');
         $errors = $server->validate($ast);

tests/Type/DefinitionTest.php

@@ -243,11 +243,11 @@ class DefinitionTest extends \PHPUnit_Framework_TestCase
 
         $value = $enumTypeWithDeprecatedValue->getValues()[0];
 
-        $this->assertEquals([
+        $this->assertArraySubset([
             'name' => 'foo',
             'description' => null,
             'deprecationReason' => 'Just because',
-            'value' => 'foo'
+            'value' => 'foo',
         ], (array) $value);
 
         $this->assertEquals(true, $value->isDeprecated());
@@ -284,8 +284,8 @@ class DefinitionTest extends \PHPUnit_Framework_TestCase
         $actual = $EnumTypeWithNullishValue->getValues();
 
         $this->assertEquals(count($expected), count($actual));
-        $this->assertEquals($expected[0], (array)$actual[0]);
+        $this->assertArraySubset($expected[0], (array)$actual[0]);
-        $this->assertEquals($expected[1], (array)$actual[1]);
+        $this->assertArraySubset($expected[1], (array)$actual[1]);
     }
 
     /**

tests/Type/IntrospectionTest.php

@@ -24,7 +24,7 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
         $emptySchema = new Schema([
             'query' => new ObjectType([
                 'name' => 'QueryRoot',
-                'fields' => []
+                'fields' => ['a' => Type::string()]
             ])
         ]);
 
@@ -42,7 +42,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                 ),
                             'types' =>
                                 array (
-                                    0 =>
                                     array (
                                         'kind' => 'OBJECT',
                                         'name' => 'QueryRoot',
@@ -52,9 +51,29 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                             ),
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
-                                            'fields' => Array ()
+                                        'fields' => array (
+                                            array (
+                                                'name' => 'a',
+                                                'args' => array(),
+                                                'type' => array(
+                                                    'kind' => 'SCALAR',
+                                                    'name' => 'String',
+                                                    'ofType' => null
+                                                ),
+                                                'isDeprecated' => false,
+                                                'deprecationReason' => null,
+                                            )
+                                        )
+                                    ),
+                                    array (
+                                        'kind' => 'SCALAR',
+                                        'name' => 'String',
+                                        'fields' => NULL,
+                                        'inputFields' => NULL,
+                                        'interfaces' => NULL,
+                                        'enumValues' => NULL,
+                                        'possibleTypes' => NULL,
                                     ),
-                                    1 =>
                                     array (
                                         'kind' => 'OBJECT',
                                         'name' => '__Schema',
@@ -108,7 +127,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                                         'isDeprecated' => false,
                                                         'deprecationReason' => NULL,
                                                     ),
-                                                    2 =>
                                                     array (
                                                         'name' => 'mutationType',
                                                         'args' =>
@@ -122,7 +140,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                                         'isDeprecated' => false,
                                                         'deprecationReason' => NULL,
                                                     ),
-                                                    3 =>
                                                     array (
                                                         'name' => 'subscriptionType',
                                                         'args' =>
@@ -136,7 +153,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                                         'isDeprecated' => false,
                                                         'deprecationReason' => NULL,
                                                     ),
-                                                    4 =>
                                                     array (
                                                         'name' => 'directives',
                                                         'args' =>
@@ -173,7 +189,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    2 =>
                                     array (
                                         'kind' => 'OBJECT',
                                         'name' => '__Type',
@@ -388,7 +403,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    3 =>
                                     array (
                                         'kind' => 'ENUM',
                                         'name' => '__TypeKind',
@@ -448,17 +462,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                             ),
                                         'possibleTypes' => NULL,
                                     ),
-                                    4 =>
-                                        array (
-                                            'kind' => 'SCALAR',
-                                            'name' => 'String',
-                                            'fields' => NULL,
-                                            'inputFields' => NULL,
-                                            'interfaces' => NULL,
-                                            'enumValues' => NULL,
-                                            'possibleTypes' => NULL,
-                                        ),
-                                    5 =>
                                     array (
                                         'kind' => 'SCALAR',
                                         'name' => 'Boolean',
@@ -468,7 +471,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    6 =>
                                     array (
                                         'kind' => 'OBJECT',
                                         'name' => '__Field',
@@ -596,7 +598,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    7 =>
                                     array (
                                         'kind' => 'OBJECT',
                                         'name' => '__InputValue',
@@ -676,7 +677,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    8 =>
                                     array (
                                         'kind' => 'OBJECT',
                                         'name' => '__EnumValue',
@@ -756,7 +756,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    9 =>
                                     array (
                                         'kind' => 'OBJECT',
                                         'name' => '__Directive',
@@ -919,7 +918,6 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    10 =>
                                     array (
                                         'kind' => 'ENUM',
                                         'name' => '__DirectiveLocation',
@@ -973,7 +971,7 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                             ),
                                         'possibleTypes' => NULL,
                                     ),
-                                    11 => array (
+                                    array (
                                         'kind' => 'SCALAR',
                                         'name' => 'ID',
                                         'fields' => NULL,
@@ -982,7 +980,7 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    12 => array (
+                                    array (
                                         'kind' => 'SCALAR',
                                         'name' => 'Float',
                                         'fields' => NULL,
@@ -991,7 +989,7 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
                                         'enumValues' => NULL,
                                         'possibleTypes' => NULL,
                                     ),
-                                    13 => array (
+                                    array (
                                         'kind' => 'SCALAR',
                                         'name' => 'Int',
                                         'fields' => NULL,
@@ -1491,7 +1489,7 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
     {
         $QueryRoot = new ObjectType([
             'name' => 'QueryRoot',
-            'fields' => []
+            'fields' => ['a' => Type::string()]
         ]);
 
         $schema = new Schema(['query' => $QueryRoot]);
@@ -1551,7 +1549,7 @@ class IntrospectionTest extends \PHPUnit_Framework_TestCase
     {
         $QueryRoot = new ObjectType([
             'name' => 'QueryRoot',
-            'fields' => []
+            'fields' => ['a' => Type::string()]
         ]);
 
         $schema = new Schema(['query' => $QueryRoot]);

tests/Utils/ExtractTypesTest.php

@@ -318,7 +318,7 @@ class ExtractTypesTest extends \PHPUnit_Framework_TestCase
     {
         $otherUserType = new ObjectType([
             'name' => 'User',
-            'fields' => []
+            'fields' => ['a' => Type::string()]
         ]);
 
         $queryType = new ObjectType([