feature #45072 [Validator] Allow creating constraints with required arguments (norkunas)

This PR was merged into the 6.1 branch.

Discussion
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[Validator] Allow creating constraints with required arguments

| Q             | A
| ------------- | ---
| Branch?       | 6.1
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       | N/A
| License       | MIT
| Doc PR        | symfony/symfony-docs#...

Before PHP8 validation constraint usage was only possible with providing options as an array, but now with native PHP attributes we can provide as named arguments. And to require some arguments overriding `getRequiredOptions` method in Constraint was necessary to get proper validation. But since PHP8.1 we can just make arguments required in the Attribute constructor and try to unpack them because it is possible now.

Commits
-------

f22433fb7a [Validator] Allow creating constraints with required arguments

Author: fabpot

Attribute/HasNamedArguments.php

@@ -0,0 +1,17 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Validator\Attribute;
+
+#[\Attribute(\Attribute::TARGET_METHOD)]
+final class HasNamedArguments
+{
+}

CHANGELOG.md

@@ -7,6 +7,7 @@ CHANGELOG
  * Deprecate `Constraint::$errorNames`, use `Constraint::ERROR_NAMES` instead
  * Deprecate constraint `ExpressionLanguageSyntax`, use `ExpressionSyntax` instead
  * Add method `__toString()` to `ConstraintViolationInterface` & `ConstraintViolationListInterface`
+ * Allow creating constraints with required arguments
 
 6.0
 ---

Mapping/Loader/AbstractLoader.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Validator\Mapping\Loader;
 
+use Symfony\Component\Validator\Attribute\HasNamedArguments;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\Exception\MappingException;
 
@@ -34,6 +35,11 @@ abstract class AbstractLoader implements LoaderInterface
 
     protected $namespaces = [];
 
+    /**
+     * @var array<class-string, bool>
+     */
+    private array $namedArgumentsCache = [];
+
     /**
      * Adds a namespace alias.
      *
@@ -78,6 +84,10 @@ protected function newConstraint(string $name, mixed $options = null): Constrain
             $className = self::DEFAULT_NAMESPACE.$name;
         }
 
+        if ($this->namedArgumentsCache[$className] ??= (bool) (new \ReflectionMethod($className, '__construct'))->getAttributes(HasNamedArguments::class)) {
+            return new $className(...$options);
+        }
+
         return new $className($options);
     }
 }

Tests/Fixtures/ConstraintWithRequiredArgument.php

@@ -0,0 +1,29 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Validator\Tests\Fixtures;
+
+use Symfony\Component\Validator\Attribute\HasNamedArguments;
+use Symfony\Component\Validator\Constraint;
+
+#[\Attribute]
+final class ConstraintWithRequiredArgument extends Constraint
+{
+    public string $requiredArg;
+
+    #[HasNamedArguments]
+    public function __construct(string $requiredArg, array $groups = null, mixed $payload = null)
+    {
+        parent::__construct([], $groups, $payload);
+
+        $this->requiredArg = $requiredArg;
+    }
+}

Tests/Fixtures/Entity_81.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\Component\Validator\Tests\Fixtures;
+
+class Entity_81
+{
+    public $title;
+}

Tests/Mapping/Loader/XmlFileLoaderTest.php

@@ -28,6 +28,8 @@
 use Symfony\Component\Validator\Tests\Fixtures\Annotation\GroupSequenceProviderEntity;
 use Symfony\Component\Validator\Tests\Fixtures\ConstraintA;
 use Symfony\Component\Validator\Tests\Fixtures\ConstraintB;
+use Symfony\Component\Validator\Tests\Fixtures\ConstraintWithRequiredArgument;
+use Symfony\Component\Validator\Tests\Fixtures\Entity_81;
 
 class XmlFileLoaderTest extends TestCase
 {
@@ -98,6 +100,19 @@ public function testLoadClassMetadataWithNonStrings()
         $this->assertFalse($constraints[0]->match);
     }
 
+    public function testLoadClassMetadataWithRequiredArguments()
+    {
+        $loader = new XmlFileLoader(__DIR__.'/constraint-mapping-required-arg.xml');
+        $metadata = new ClassMetadata(Entity_81::class);
+
+        $loader->loadClassMetadata($metadata);
+
+        $expected = new ClassMetadata(Entity_81::class);
+        $expected->addPropertyConstraint('title', new ConstraintWithRequiredArgument('X'));
+
+        $this->assertEquals($expected, $metadata);
+    }
+
     public function testLoadGroupSequenceProvider()
     {
         $loader = new XmlFileLoader(__DIR__.'/constraint-mapping.xml');

Tests/Mapping/Loader/YamlFileLoaderTest.php

@@ -25,6 +25,8 @@
 use Symfony\Component\Validator\Tests\Fixtures\Annotation\GroupSequenceProviderEntity;
 use Symfony\Component\Validator\Tests\Fixtures\ConstraintA;
 use Symfony\Component\Validator\Tests\Fixtures\ConstraintB;
+use Symfony\Component\Validator\Tests\Fixtures\ConstraintWithRequiredArgument;
+use Symfony\Component\Validator\Tests\Fixtures\Entity_81;
 
 class YamlFileLoaderTest extends TestCase
 {
@@ -138,6 +140,19 @@ public function testLoadClassMetadataWithConstants()
         $this->assertEquals($expected, $metadata);
     }
 
+    public function testLoadClassMetadataWithRequiredArguments()
+    {
+        $loader = new YamlFileLoader(__DIR__.'/constraint-mapping-required-arg.yml');
+        $metadata = new ClassMetadata(Entity_81::class);
+
+        $loader->loadClassMetadata($metadata);
+
+        $expected = new ClassMetadata(Entity_81::class);
+        $expected->addPropertyConstraint('title', new ConstraintWithRequiredArgument('X'));
+
+        $this->assertEquals($expected, $metadata);
+    }
+
     public function testLoadGroupSequenceProvider()
     {
         $loader = new YamlFileLoader(__DIR__.'/constraint-mapping.yml');

Tests/Mapping/Loader/constraint-mapping-required-arg.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" ?>
+
+<constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">
+
+    <class name="Symfony\Component\Validator\Tests\Fixtures\Entity_81">
+
+        <property name="title">
+            <constraint name="Symfony\Component\Validator\Tests\Fixtures\ConstraintWithRequiredArgument">
+                <option name="requiredArg">X</option>
+            </constraint>
+        </property>
+    </class>
+
+</constraint-mapping>

Tests/Mapping/Loader/constraint-mapping-required-arg.yml

@@ -0,0 +1,5 @@
+Symfony\Component\Validator\Tests\Fixtures\Entity_81:
+  properties:
+    title:
+      - Symfony\Component\Validator\Tests\Fixtures\ConstraintWithRequiredArgument:
+          requiredArg: 'X'