Add scalar Null (#15)

Author: spawnia

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+## v5.1.0
+
+### Added
+
+- Add scalar `Null`
+
 ## v5.0.1
 
 ###  Fixed

README.md

@@ -24,21 +24,25 @@ A [RFC 5321](https://tools.ietf.org/html/rfc5321) compliant email.
 
 ### [JSON](src/JSON.php)
 
-Arbitrary data encoded in JavaScript Object Notation. See https://www.json.org/.
+Arbitrary data encoded in JavaScript Object Notation. See https://www.json.org.
 
 ### [Mixed](src/MixedScalar.php)
 
 Loose type that allows any value. Be careful when passing in large `Int` or `Float` literals,
 as they may not be parsed correctly on the server side. Use `String` literals if you are
 dealing with really large numbers to be on the safe side.
 
+### [Null](src/NullScalar.php)
+
+Always `null`. Strictly validates value is non-null, no coercion.
+
 ### [Regex](src/Regex.php)
 
 The `Regex` class allows you to define a custom scalar that validates that the given
 value matches a regular expression.
 
 The quickest way to define a custom scalar is the `make` factory method. Just provide
-a name and a regular expression and you will receive a ready-to-use custom regex scalar.
+a name and a regular expression, you will receive a ready-to-use custom regex scalar.
 
 ```php
 use MLL\GraphQLScalars\Regex;
@@ -78,7 +82,7 @@ DESCRIPTION;
 ### [StringScalar](src/StringScalar.php)
 
 The `StringScalar` encapsulates all the boilerplate associated with creating a string-based Scalar type.
-It does the proper string checking for you and let's you focus on the minimal logic that is specific to your use case.
+It performs basic checks and coercion, you can focus on the minimal logic that is specific to your use case.
 
 All you have to specify is a function that checks if the given string is valid.
 Use the factory method `make` to generate an instance on the fly.

composer.json

@@ -16,10 +16,10 @@
   "require": {
     "php": "^7.4 || ^8",
     "ext-json": "*",
-    "egulias/email-validator": "^2 || ^3",
+    "egulias/email-validator": "^2.1.17 || ^3",
     "spatie/regex": "^1.4",
     "thecodingmachine/safe": "^1.3",
-    "webonyx/graphql-php": "^0.13 || ^14"
+    "webonyx/graphql-php": "^0.13.9 || ^14"
   },
   "require-dev": {
     "ergebnis/composer-normalize": "^2.16",

src/Email.php

@@ -1,6 +1,4 @@
-<?php
-
-declare(strict_types=1);
+<?php declare(strict_types=1);
 
 namespace MLL\GraphQLScalars;
 

src/JSON.php

@@ -1,6 +1,4 @@
-<?php
-
-declare(strict_types=1);
+<?php declare(strict_types=1);
 
 namespace MLL\GraphQLScalars;
 
@@ -12,7 +10,7 @@
 class JSON extends ScalarType
 {
     public $description /** @lang Markdown */
-        = 'Arbitrary data encoded in JavaScript Object Notation. See https://www.json.org/.';
+        = 'Arbitrary data encoded in JavaScript Object Notation. See https://www.json.org.';
 
     public function serialize($value): string
     {

src/MixedScalar.php

@@ -1,6 +1,4 @@
-<?php
-
-declare(strict_types=1);
+<?php declare(strict_types=1);
 
 namespace MLL\GraphQLScalars;
 

src/NullScalar.php

@@ -0,0 +1,55 @@
+<?php declare(strict_types=1);
+
+namespace MLL\GraphQLScalars;
+
+use GraphQL\Error\Error;
+use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\NullValueNode;
+use GraphQL\Type\Definition\ScalarType;
+use GraphQL\Utils\Utils;
+
+class NullScalar extends ScalarType
+{
+    public $name = 'Null';
+
+    public $description /** @lang Markdown */
+        = 'Always `null`. Strictly validates value is non-null, no coercion.';
+
+    public function serialize($value)
+    {
+        if (null !== $value) {
+            throw new InvariantViolation(static::notNullMessage($value));
+        }
+
+        return null;
+    }
+
+    public function parseValue($value)
+    {
+        if (null !== $value) {
+            throw new Error(static::notNullMessage($value));
+        }
+
+        return null;
+    }
+
+    public function parseLiteral($valueNode, ?array $variables = null)
+    {
+        if (! $valueNode instanceof NullValueNode) {
+            // Intentionally without message, as all information is already present in the wrapped error
+            throw new Error('');
+        }
+
+        return null;
+    }
+
+    /**
+     * @param mixed $value any non-null value
+     */
+    public static function notNullMessage($value): string
+    {
+        $notNull = Utils::printSafe($value);
+
+        return "Expected null, got: {$notNull}";
+    }
+}

src/Regex.php

@@ -1,6 +1,4 @@
-<?php
-
-declare(strict_types=1);
+<?php declare(strict_types=1);
 
 namespace MLL\GraphQLScalars;
 

src/StringScalar.php

@@ -1,6 +1,4 @@
-<?php
-
-declare(strict_types=1);
+<?php declare(strict_types=1);
 
 namespace MLL\GraphQLScalars;
 

src/Utils.php

@@ -1,6 +1,4 @@
-<?php
-
-declare(strict_types=1);
+<?php declare(strict_types=1);
 
 namespace MLL\GraphQLScalars;