Throw SerializationError over client safe Error when failing to serialize scalars

Resolves #570

Author: spawnia

CHANGELOG.md

@@ -14,6 +14,7 @@ You can find and compare releases at the [GitHub release page](https://github.co
 - PHP version required: 7.4+
 - Propagate error message and stack trace for why leaf value serialization failed
 - Do not throw client safe `Error` when failing to serialize an Enum type
+- Throw `SerializationError` over client safe `Error` when failing to serialize scalars
 
 ### Added
 

examples/01-blog/Blog/Type/Scalar/EmailType.php

@@ -5,45 +5,27 @@
 namespace GraphQL\Examples\Blog\Type\Scalar;
 
 use GraphQL\Error\Error;
-use GraphQL\Language\AST\BooleanValueNode;
-use GraphQL\Language\AST\FloatValueNode;
-use GraphQL\Language\AST\IntValueNode;
+use GraphQL\Error\SerializationError;
 use GraphQL\Language\AST\Node;
-use GraphQL\Language\AST\NullValueNode;
 use GraphQL\Language\AST\StringValueNode;
 use GraphQL\Type\Definition\ScalarType;
 use GraphQL\Utils\Utils;
-use UnexpectedValueException;
 
 use function filter_var;
 
 use const FILTER_VALIDATE_EMAIL;
 
 class EmailType extends ScalarType
 {
-    /**
-     * Serializes an internal value to include in a response.
-     *
-     * Should throw an exception on invalid values.
-     *
-     * @param mixed $value
-     */
     public function serialize($value): string
     {
         if (! $this->isEmail($value)) {
-            throw new UnexpectedValueException('Cannot represent value as email: ' . Utils::printSafe($value));
+            throw new SerializationError('Cannot represent value as email: ' . Utils::printSafe($value));
         }
 
         return $value;
     }
 
-    /**
-     * Parses an externally provided value (query variable) to use as an input.
-     *
-     * Should throw an exception with a client friendly message on invalid values, @see ClientAware.
-     *
-     * @param mixed $value
-     */
     public function parseValue($value): string
     {
         if (! $this->isEmail($value)) {
@@ -53,14 +35,6 @@ public function parseValue($value): string
         return $value;
     }
 
-    /**
-     * Parses an externally provided literal value (hardcoded in GraphQL query) to use as an input.
-     *
-     * Should throw an exception with a client friendly message on invalid value nodes, @see ClientAware.
-     *
-     * @param IntValueNode|FloatValueNode|StringValueNode|BooleanValueNode|NullValueNode $valueNode
-     * @param array<string, mixed>|null                                                  $variables
-     */
     public function parseLiteral(Node $valueNode, ?array $variables = null): string
     {
         // Note: throwing GraphQL\Error\Error vs \UnexpectedValueException to benefit from GraphQL

examples/01-blog/Blog/Type/Scalar/UrlType.php

@@ -5,15 +5,11 @@
 namespace GraphQL\Examples\Blog\Type\Scalar;
 
 use GraphQL\Error\Error;
-use GraphQL\Language\AST\BooleanValueNode;
-use GraphQL\Language\AST\FloatValueNode;
-use GraphQL\Language\AST\IntValueNode;
+use GraphQL\Error\SerializationError;
 use GraphQL\Language\AST\Node;
-use GraphQL\Language\AST\NullValueNode;
 use GraphQL\Language\AST\StringValueNode;
 use GraphQL\Type\Definition\ScalarType;
 use GraphQL\Utils\Utils;
-use UnexpectedValueException;
 
 use function filter_var;
 use function is_string;
@@ -22,34 +18,16 @@
 
 class UrlType extends ScalarType
 {
-    /**
-     * Serializes an internal value to include in a response.
-     *
-     * Should throw an exception on invalid values.
-     *
-     * @param mixed $value
-     *
-     * @return mixed
-     */
-    public function serialize($value)
+    public function serialize($value): string
     {
         if (! $this->isUrl($value)) {
-            throw new UnexpectedValueException('Cannot represent value as URL: ' . Utils::printSafe($value));
+            throw new SerializationError('Cannot represent value as URL: ' . Utils::printSafe($value));
         }
 
         return $value;
     }
 
-    /**
-     * Parses an externally provided value (query variable) to use as an input.
-     *
-     * Should throw an exception with a client friendly message on invalid values, @see ClientAware.
-     *
-     * @param mixed $value
-     *
-     * @return mixed
-     */
-    public function parseValue($value)
+    public function parseValue($value): string
     {
         if (! $this->isUrl($value)) {
             throw new Error('Cannot represent value as URL: ' . Utils::printSafe($value));
@@ -58,15 +36,7 @@ public function parseValue($value)
         return $value;
     }
 
-    /**
-     * Parses an externally provided literal value (hardcoded in GraphQL query) to use as an input.
-     *
-     * Should throw an exception with a client friendly message on invalid value nodes, @see ClientAware.
-     *
-     * @param IntValueNode|FloatValueNode|StringValueNode|BooleanValueNode|NullValueNode $valueNode
-     * @param array<string, mixed>|null                                                  $variables
-     */
-    public function parseLiteral(Node $valueNode, ?array $variables = null): ?string
+    public function parseLiteral(Node $valueNode, ?array $variables = null): string
     {
         // Throwing GraphQL\Error\Error to benefit from GraphQL error location in query
         if (! ($valueNode instanceof StringValueNode)) {

phpcs.xml.dist

@@ -21,6 +21,8 @@
         <exclude name="SlevomatCodingStandard.PHP.RequireExplicitAssertion.RequiredExplicitAssertion" />
         <exclude name="SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingAnyTypeHint" />
         <exclude name="SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingNativeTypeHint" />
+        <exclude name="SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingTraversableTypeHintSpecification" />
+        <exclude name="SlevomatCodingStandard.TypeHints.PropertyTypeHint.MissingAnyTypeHint" />
         <exclude name="SlevomatCodingStandard.TypeHints.PropertyTypeHint.MissingNativeTypeHint" />
         <exclude name="SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingAnyTypeHint" />
         <exclude name="SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingNativeTypeHint" />

src/Error/SerializationError.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace GraphQL\Error;
+
+use Exception;
+
+/**
+ * Thrown when failing to serialize a scalar value.
+ *
+ * Not generally safe for clients, as the wrong given value could
+ * be something not intended to ever be seen by clients.
+ */
+class SerializationError extends Exception
+{
+}

src/Type/Definition/BooleanType.php

@@ -4,7 +4,6 @@
 
 namespace GraphQL\Type\Definition;
 
-use Exception;
 use GraphQL\Error\Error;
 use GraphQL\Language\AST\BooleanValueNode;
 use GraphQL\Language\AST\Node;
@@ -14,33 +13,22 @@
 
 class BooleanType extends ScalarType
 {
-    /** @var string */
     public $name = Type::BOOLEAN;
 
-    /** @var string */
     public $description = 'The `Boolean` scalar type represents `true` or `false`.';
 
     /**
-     * Serialize the given value to a boolean.
+     * Serialize the given value to a bool.
      *
      * The GraphQL spec leaves this up to the implementations, so we just do what
      * PHP does natively to make this intuitive for developers.
-     *
-     * @param mixed $value
      */
     public function serialize($value): bool
     {
         return (bool) $value;
     }
 
-    /**
-     * @param mixed $value
-     *
-     * @return bool
-     *
-     * @throws Error
-     */
-    public function parseValue($value)
+    public function parseValue($value): bool
     {
         if (is_bool($value)) {
             return $value;
@@ -49,18 +37,13 @@ public function parseValue($value)
         throw new Error('Boolean cannot represent a non boolean value: ' . Utils::printSafe($value));
     }
 
-    /**
-     * @param mixed[]|null $variables
-     *
-     * @throws Exception
-     */
-    public function parseLiteral(Node $valueNode, ?array $variables = null)
+    public function parseLiteral(Node $valueNode, ?array $variables = null): bool
     {
-        if (! $valueNode instanceof BooleanValueNode) {
-            // Intentionally without message, as all information already in wrapped Exception
-            throw new Error();
+        if ($valueNode instanceof BooleanValueNode) {
+            return $valueNode->value;
         }
 
-        return $valueNode->value;
+        // Intentionally without message, as all information already in wrapped Exception
+        throw new Error();
     }
 }

src/Type/Definition/CustomScalarType.php

@@ -4,7 +4,6 @@
 
 namespace GraphQL\Type\Definition;
 
-use Exception;
 use GraphQL\Language\AST\Node;
 use GraphQL\Utils\AST;
 use GraphQL\Utils\Utils;
@@ -14,21 +13,11 @@
 
 class CustomScalarType extends ScalarType
 {
-    /**
-     * @param mixed $value
-     *
-     * @return mixed
-     */
     public function serialize($value)
     {
         return $this->config['serialize']($value);
     }
 
-    /**
-     * @param mixed $value
-     *
-     * @return mixed
-     */
     public function parseValue($value)
     {
         if (isset($this->config['parseValue'])) {
@@ -38,13 +27,6 @@ public function parseValue($value)
         return $value;
     }
 
-    /**
-     * @param mixed[]|null $variables
-     *
-     * @return mixed
-     *
-     * @throws Exception
-     */
     public function parseLiteral(Node $valueNode, ?array $variables = null)
     {
         if (isset($this->config['parseLiteral'])) {

src/Type/Definition/FloatType.php

@@ -4,8 +4,8 @@
 
 namespace GraphQL\Type\Definition;
 
-use Exception;
 use GraphQL\Error\Error;
+use GraphQL\Error\SerializationError;
 use GraphQL\Language\AST\FloatValueNode;
 use GraphQL\Language\AST\IntValueNode;
 use GraphQL\Language\AST\Node;
@@ -19,28 +19,21 @@
 
 class FloatType extends ScalarType
 {
-    /** @var string */
     public $name = Type::FLOAT;
 
-    /** @var string */
     public $description =
         'The `Float` scalar type represents signed double-precision fractional
 values as specified by
 [IEEE 754](http://en.wikipedia.org/wiki/IEEE_floating_point). ';
 
-    /**
-     * @param mixed $value
-     *
-     * @throws Error
-     */
     public function serialize($value): float
     {
         $float = is_numeric($value) || is_bool($value)
             ? (float) $value
             : null;
 
         if ($float === null || ! is_finite($float)) {
-            throw new Error(
+            throw new SerializationError(
                 'Float cannot represent non numeric value: ' .
                 Utils::printSafe($value)
             );
@@ -49,11 +42,6 @@ public function serialize($value): float
         return $float;
     }
 
-    /**
-     * @param mixed $value
-     *
-     * @throws Error
-     */
     public function parseValue($value): float
     {
         $float = is_float($value) || is_int($value)
@@ -70,13 +58,6 @@ public function parseValue($value): float
         return $float;
     }
 
-    /**
-     * @param mixed[]|null $variables
-     *
-     * @return float
-     *
-     * @throws Exception
-     */
     public function parseLiteral(Node $valueNode, ?array $variables = null)
     {
         if ($valueNode instanceof FloatValueNode || $valueNode instanceof IntValueNode) {