feature #28210 [Contracts] Add Translation\TranslatorInterface + decouple symfony/validator from symfony/translation (nicolas-grekas)

This PR was merged into the 4.2-dev branch.

Discussion
----------

[Contracts] Add Translation\TranslatorInterface + decouple symfony/validator from symfony/translation

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #15714, #18930
| License       | MIT
| Doc PR        | -

Let's decouple Validator from Translation component \o/!

TODO:
- [x] add `TranslatorInterface`, deprecate it from Translation
- [x] add `TranslatorTrait`, deprecating `MessageSelector`, `Internal` and `PluralizationRules`
- [x] deprecate `ValidatorBuilderInterface(LegacyTranslatorInterface)`
- [x] inject a new `identity_translator` into `translator.formatter.default`, deprecate `translator.selector`
- [x] copy tests in the Contracts namespace to ensure the `TranslatorTrait` behaves properly
- [x] figure out a way to keep throwing `InvalidArgumentException` from the component
- [x] update UPGRADING and CHANGELOG files
- [x] polish the deprecation layer (ensure all needed runtime deprecations are here)

Reviews welcome already.

Commits
-------

064e369e06 [Contracts] Add Translation\TranslatorInterface + decouple symfony/validator from symfony/translation

UPGRADE-4.2.md

@@ -149,3 +149,15 @@ Serializer
 
  * Relying on the default value (false) of the "as_collection" option is deprecated since 4.2.
    You should set it to false explicitly instead as true will be the default value in 5.0.
+
+Translation
+-----------
+
+ * The `TranslatorInterface` has been deprecated in favor of `Symfony\Contracts\Translation\TranslatorInterface`
+ * The `MessageSelector`, `Interval` and `PluralizationRules` classes have been deprecated, use `IdentityTranslator` instead
+
+Validator
+---------
+
+ * The component is now decoupled from `symfony/translation` and uses `Symfony\Contracts\Translation\TranslatorInterface` instead
+ * The `ValidatorBuilderInterface` has been deprecated and `ValidatorBuilder` made final

UPGRADE-5.0.md

@@ -146,6 +146,8 @@ Translation
 
  * The `FileDumper::setBackup()` method has been removed.
  * The `TranslationWriter::disableBackup()` method has been removed.
+ * The `TranslatorInterface` has been removed in favor of `Symfony\Contracts\Translation\TranslatorInterface`
+ * The `MessageSelector`, `Interval` and `PluralizationRules` classes have been removed, use `IdentityTranslator` instead
 
 TwigBundle
 ----------
@@ -158,6 +160,8 @@ Validator
  * The `Email::__construct()` 'strict' property has been removed. Use 'mode'=>"strict" instead.
  * Calling `EmailValidator::__construct()` method with a boolean parameter has been removed, use `EmailValidator("strict")` instead.
  * Removed the `checkDNS` and `dnsMessage` options from the `Url` constraint.
+ * The component is now decoupled from `symfony/translation` and uses `Symfony\Contracts\Translation\TranslatorInterface` instead
+ * The `ValidatorBuilderInterface` has been removed and `ValidatorBuilder` is now final
 
 Workflow
 --------

src/Symfony/Bridge/Twig/Extension/TranslationExtension.php

@@ -16,7 +16,7 @@ use Symfony\Bridge\Twig\NodeVisitor\TranslationNodeVisitor;
 use Symfony\Bridge\Twig\TokenParser\TransChoiceTokenParser;
 use Symfony\Bridge\Twig\TokenParser\TransDefaultDomainTokenParser;
 use Symfony\Bridge\Twig\TokenParser\TransTokenParser;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 use Twig\Extension\AbstractExtension;
 use Twig\NodeVisitor\NodeVisitorInterface;
 use Twig\TokenParser\AbstractTokenParser;

src/Symfony/Bridge/Twig/Tests/Extension/Fixtures/StubTranslator.php

@@ -11,7 +11,7 @@
 
 namespace Symfony\Bridge\Twig\Tests\Extension\Fixtures;
 
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 class StubTranslator implements TranslatorInterface
 {

src/Symfony/Bridge/Twig/Tests/Translation/TwigExtractorTest.php

@@ -15,6 +15,7 @@ use PHPUnit\Framework\TestCase;
 use Symfony\Bridge\Twig\Extension\TranslationExtension;
 use Symfony\Bridge\Twig\Translation\TwigExtractor;
 use Symfony\Component\Translation\MessageCatalogue;
+use Symfony\Contracts\Translation\TranslatorInterface;
 use Twig\Environment;
 use Twig\Error\Error;
 use Twig\Loader\ArrayLoader;
@@ -33,7 +34,7 @@ class TwigExtractorTest extends TestCase
             'cache' => false,
             'autoescape' => false,
         ));
-        $twig->addExtension(new TranslationExtension($this->getMockBuilder('Symfony\Component\Translation\TranslatorInterface')->getMock()));
+        $twig->addExtension(new TranslationExtension($this->getMockBuilder(TranslatorInterface::class)->getMock()));
 
         $extractor = new TwigExtractor($twig);
         $extractor->setPrefix('prefix');
@@ -82,7 +83,7 @@ class TwigExtractorTest extends TestCase
     public function testExtractSyntaxError($resources)
     {
         $twig = new Environment($this->getMockBuilder('Twig\Loader\LoaderInterface')->getMock());
-        $twig->addExtension(new TranslationExtension($this->getMockBuilder('Symfony\Component\Translation\TranslatorInterface')->getMock()));
+        $twig->addExtension(new TranslationExtension($this->getMockBuilder(TranslatorInterface::class)->getMock()));
 
         $extractor = new TwigExtractor($twig);
 
@@ -124,7 +125,7 @@ class TwigExtractorTest extends TestCase
             'cache' => false,
             'autoescape' => false,
         ));
-        $twig->addExtension(new TranslationExtension($this->getMockBuilder('Symfony\Component\Translation\TranslatorInterface')->getMock()));
+        $twig->addExtension(new TranslationExtension($this->getMockBuilder(TranslatorInterface::class)->getMock()));
 
         $extractor = new TwigExtractor($twig);
         $catalogue = new MessageCatalogue('en');

src/Symfony/Bridge/Twig/composer.json

@@ -29,7 +29,7 @@
         "symfony/polyfill-intl-icu": "~1.0",
         "symfony/routing": "~3.4|~4.0",
         "symfony/templating": "~3.4|~4.0",
-        "symfony/translation": "~3.4|~4.0",
+        "symfony/translation": "~4.2",
         "symfony/yaml": "~3.4|~4.0",
         "symfony/security": "~3.4|~4.0",
         "symfony/security-acl": "~2.8|~3.0",
@@ -41,8 +41,9 @@
         "symfony/workflow": "~3.4|~4.0"
     },
     "conflict": {
+        "symfony/console": "<3.4",
         "symfony/form": "<4.1.2",
-        "symfony/console": "<3.4"
+        "symfony/translation": "<4.2"
     },
     "suggest": {
         "symfony/finder": "",

src/Symfony/Bundle/FrameworkBundle/CacheWarmer/TranslationsCacheWarmer.php

@@ -15,7 +15,7 @@ use Psr\Container\ContainerInterface;
 use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
 use Symfony\Component\HttpKernel\CacheWarmer\CacheWarmerInterface;
 use Symfony\Component\HttpKernel\CacheWarmer\WarmableInterface;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * Generates the catalogues for translations.

src/Symfony/Bundle/FrameworkBundle/Command/TranslationDebugCommand.php

@@ -26,7 +26,7 @@ use Symfony\Component\Translation\LoggingTranslator;
 use Symfony\Component\Translation\MessageCatalogue;
 use Symfony\Component\Translation\Reader\TranslationReaderInterface;
 use Symfony\Component\Translation\Translator;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * Helps finding unused or missing translation messages in a given locale

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/LoggingTranslatorPass.php

@@ -15,7 +15,7 @@ use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
 use Symfony\Component\Translation\TranslatorBagInterface;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Abdellatif Ait boudad <a.aitboudad@gmail.com>

src/Symfony/Bundle/FrameworkBundle/Resources/config/identity_translator.xml

@@ -6,11 +6,13 @@
     <services>
         <defaults public="false" />
 
-        <service id="translator" class="Symfony\Component\Translation\IdentityTranslator" public="true">
-            <argument type="service" id="translator.selector" />
-        </service>
+        <service id="translator" class="Symfony\Component\Translation\IdentityTranslator" public="true" />
         <service id="Symfony\Component\Translation\TranslatorInterface" alias="translator" />
+        <service id="Symfony\Contracts\Translation\TranslatorInterface" alias="translator" />
 
-        <service id="translator.selector" class="Symfony\Component\Translation\MessageSelector" />
+        <service id="identity_translator" class="Symfony\Component\Translation\IdentityTranslator" />
+        <service id="translator.selector" class="Symfony\Component\Translation\MessageSelector">
+            <deprecated>The "%service_id%" service is deprecated since Symfony 4.2, use "identity_translator" instead.</deprecated>
+        </service>
     </services>
 </container>

src/Symfony/Bundle/FrameworkBundle/Resources/config/translation.xml

@@ -21,6 +21,7 @@
             </call>
         </service>
         <service id="Symfony\Component\Translation\TranslatorInterface" alias="translator" />
+        <service id="Symfony\Contracts\Translation\TranslatorInterface" alias="translator" />
 
         <service id="translator.logging" class="Symfony\Component\Translation\LoggingTranslator">
             <argument type="service" id="translator.logging.inner" />
@@ -29,7 +30,7 @@
         </service>
 
         <service id="translator.formatter.default" class="Symfony\Component\Translation\Formatter\MessageFormatter">
-            <argument type="service" id="translator.selector" />
+            <argument type="service" id="identity_translator" />
         </service>
 
         <service id="translation.loader.php" class="Symfony\Component\Translation\Loader\PhpFileLoader">

src/Symfony/Bundle/FrameworkBundle/Templating/Helper/TranslatorHelper.php

@@ -12,7 +12,7 @@
 namespace Symfony\Bundle\FrameworkBundle\Templating\Helper;
 
 use Symfony\Component\Templating\Helper\Helper;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Fabien Potencier <fabien@symfony.com>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/DataCollectorTranslatorPassTest.php

@@ -15,7 +15,7 @@ use PHPUnit\Framework\TestCase;
 use Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\DataCollectorTranslatorPass;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Reference;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 class DataCollectorTranslatorPassTest extends TestCase
 {

src/Symfony/Bundle/FrameworkBundle/Tests/Templating/Helper/Fixtures/StubTranslator.php

@@ -11,7 +11,7 @@
 
 namespace Symfony\Bundle\FrameworkBundle\Tests\Templating\Helper\Fixtures;
 
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 class StubTranslator implements TranslatorInterface
 {

src/Symfony/Bundle/FrameworkBundle/composer.json

@@ -47,7 +47,7 @@
         "symfony/security-csrf": "~3.4|~4.0",
         "symfony/serializer": "^4.1",
         "symfony/stopwatch": "~3.4|~4.0",
-        "symfony/translation": "~3.4|~4.0",
+        "symfony/translation": "~4.2",
         "symfony/templating": "~3.4|~4.0",
         "symfony/validator": "^4.1",
         "symfony/var-dumper": "~3.4|~4.0",
@@ -71,7 +71,7 @@
         "symfony/property-info": "<3.4",
         "symfony/serializer": "<4.1",
         "symfony/stopwatch": "<3.4",
-        "symfony/translation": "<3.4",
+        "symfony/translation": "<4.2",
         "symfony/twig-bridge": "<4.1.1",
         "symfony/validator": "<4.1",
         "symfony/workflow": "<4.1"

src/Symfony/Bundle/TwigBundle/DependencyInjection/TwigExtension.php

@@ -19,6 +19,7 @@ use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\HttpKernel\DependencyInjection\Extension;
+use Symfony\Component\Translation\Translator;
 use Twig\Extension\ExtensionInterface;
 use Twig\Extension\RuntimeExtensionInterface;
 use Twig\Loader\LoaderInterface;
@@ -48,7 +49,7 @@ class TwigExtension extends Extension
             $loader->load('console.xml');
         }
 
-        if (!interface_exists('Symfony\Component\Translation\TranslatorInterface')) {
+        if (!class_exists(Translator::class)) {
             $container->removeDefinition('twig.translation.extractor');
         }
 

src/Symfony/Bundle/TwigBundle/composer.json

@@ -41,7 +41,8 @@
     },
     "conflict": {
         "symfony/dependency-injection": "<4.1",
-        "symfony/framework-bundle": "<4.1"
+        "symfony/framework-bundle": "<4.1",
+        "symfony/translation": "<4.2"
     },
     "autoload": {
         "psr-4": { "Symfony\\Bundle\\TwigBundle\\": "" },

src/Symfony/Component/Form/Extension/Csrf/CsrfExtension.php

@@ -13,7 +13,7 @@ namespace Symfony\Component\Form\Extension\Csrf;
 
 use Symfony\Component\Form\AbstractExtension;
 use Symfony\Component\Security\Csrf\CsrfTokenManagerInterface;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * This extension protects forms by using a CSRF token.

src/Symfony/Component/Form/Extension/Csrf/EventListener/CsrfValidationListener.php

@@ -18,7 +18,7 @@ use Symfony\Component\Form\FormEvents;
 use Symfony\Component\Form\Util\ServerParams;
 use Symfony\Component\Security\Csrf\CsrfToken;
 use Symfony\Component\Security\Csrf\CsrfTokenManagerInterface;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Bernhard Schussek <bschussek@gmail.com>

src/Symfony/Component/Form/Extension/Csrf/Type/FormTypeCsrfExtension.php

@@ -19,7 +19,7 @@ use Symfony\Component\Form\FormView;
 use Symfony\Component\Form\Util\ServerParams;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 use Symfony\Component\Security\Csrf\CsrfTokenManagerInterface;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Bernhard Schussek <bschussek@gmail.com>

src/Symfony/Component/Form/Extension/Validator/Type/UploadValidatorExtension.php

@@ -14,7 +14,7 @@ namespace Symfony\Component\Form\Extension\Validator\Type;
 use Symfony\Component\Form\AbstractTypeExtension;
 use Symfony\Component\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Abdellatif Ait boudad <a.aitboudad@gmail.com>

src/Symfony/Component/Form/Tests/Extension/Csrf/Type/FormTypeCsrfExtensionTest.php

@@ -17,6 +17,8 @@ use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Form\FormError;
 use Symfony\Component\Form\Test\TypeTestCase;
 use Symfony\Component\Security\Csrf\CsrfToken;
+use Symfony\Component\Security\Csrf\CsrfTokenManagerInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 class FormTypeCsrfExtensionTest_ChildType extends AbstractType
 {
@@ -42,8 +44,8 @@ class FormTypeCsrfExtensionTest extends TypeTestCase
 
     protected function setUp()
     {
-        $this->tokenManager = $this->getMockBuilder('Symfony\Component\Security\Csrf\CsrfTokenManagerInterface')->getMock();
-        $this->translator = $this->getMockBuilder('Symfony\Component\Translation\TranslatorInterface')->getMock();
+        $this->tokenManager = $this->getMockBuilder(CsrfTokenManagerInterface::class)->getMock();
+        $this->translator = $this->getMockBuilder(TranslatorInterface::class)->getMock();
 
         parent::setUp();
     }

src/Symfony/Component/Form/Tests/Extension/Validator/Type/UploadValidatorExtensionTest.php

@@ -15,12 +15,13 @@ use Symfony\Component\Form\Extension\Validator\Type\UploadValidatorExtension;
 use Symfony\Component\Form\Test\TypeTestCase;
 use Symfony\Component\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 class UploadValidatorExtensionTest extends TypeTestCase
 {
     public function testPostMaxSizeTranslation()
     {
-        $translator = $this->getMockBuilder('Symfony\Component\Translation\TranslatorInterface')->getMock();
+        $translator = $this->getMockBuilder(TranslatorInterface::class)->getMock();
 
         $translator->expects($this->any())
             ->method('trans')

src/Symfony/Component/Form/composer.json

@@ -33,7 +33,7 @@
         "symfony/http-foundation": "~3.4|~4.0",
         "symfony/http-kernel": "~3.4|~4.0",
         "symfony/security-csrf": "~3.4|~4.0",
-        "symfony/translation": "~3.4|~4.0",
+        "symfony/translation": "~4.2",
         "symfony/var-dumper": "~3.4|~4.0"
     },
     "conflict": {
@@ -42,6 +42,7 @@
         "symfony/doctrine-bridge": "<3.4",
         "symfony/framework-bundle": "<3.4",
         "symfony/http-kernel": "<3.4",
+        "symfony/translation": "<4.2",
         "symfony/twig-bridge": "<3.4.5|<4.0.5,>=4.0"
     },
     "suggest": {

src/Symfony/Component/HttpKernel/EventListener/TranslatorListener.php

@@ -17,7 +17,7 @@ use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\HttpKernel\Event\FinishRequestEvent;
 use Symfony\Component\HttpKernel\Event\GetResponseEvent;
 use Symfony\Component\HttpKernel\KernelEvents;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * Synchronizes the locale between the request and the translator.

src/Symfony/Component/HttpKernel/Tests/EventListener/TranslatorListenerTest.php

@@ -17,6 +17,7 @@ use Symfony\Component\HttpKernel\Event\FinishRequestEvent;
 use Symfony\Component\HttpKernel\Event\GetResponseEvent;
 use Symfony\Component\HttpKernel\EventListener\TranslatorListener;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 class TranslatorListenerTest extends TestCase
 {
@@ -26,7 +27,7 @@ class TranslatorListenerTest extends TestCase
 
     protected function setUp()
     {
-        $this->translator = $this->getMockBuilder('Symfony\Component\Translation\TranslatorInterface')->getMock();
+        $this->translator = $this->getMockBuilder(TranslatorInterface::class)->getMock();
         $this->requestStack = $this->getMockBuilder('Symfony\Component\HttpFoundation\RequestStack')->getMock();
         $this->listener = new TranslatorListener($this->translator, $this->requestStack);
     }

src/Symfony/Component/HttpKernel/composer.json

@@ -37,7 +37,7 @@
         "symfony/routing": "~3.4|~4.0",
         "symfony/stopwatch": "~3.4|~4.0",
         "symfony/templating": "~3.4|~4.0",
-        "symfony/translation": "~3.4|~4.0",
+        "symfony/translation": "~4.2",
         "symfony/var-dumper": "^4.1.1",
         "psr/cache": "~1.0"
     },
@@ -47,6 +47,7 @@
     "conflict": {
         "symfony/config": "<3.4",
         "symfony/dependency-injection": "<4.2",
+        "symfony/translation": "<4.2",
         "symfony/var-dumper": "<4.1.1",
         "twig/twig": "<1.34|<2.4,>=2"
     },

src/Symfony/Component/Translation/CHANGELOG.md

@@ -5,6 +5,8 @@ CHANGELOG
 -----
 
  * Started using ICU parent locales as fallback locales.
+ * deprecated `TranslatorInterface` in favor of `Symfony\Contracts\Translation\TranslatorInterface`
+ * deprecated `MessageSelector`, `Interval` and `PluralizationRules`; use `IdentityTranslator` instead
 
 4.1.0
 -----

src/Symfony/Component/Translation/DataCollectorTranslator.php

@@ -12,11 +12,13 @@
 namespace Symfony\Component\Translation;
 
 use Symfony\Component\Translation\Exception\InvalidArgumentException;
+use Symfony\Component\Translation\TranslatorInterface as LegacyTranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Abdellatif Ait boudad <a.aitboudad@gmail.com>
  */
-class DataCollectorTranslator implements TranslatorInterface, TranslatorBagInterface
+class DataCollectorTranslator implements LegacyTranslatorInterface, TranslatorBagInterface
 {
     const MESSAGE_DEFINED = 0;
     const MESSAGE_MISSING = 1;

src/Symfony/Component/Translation/Formatter/MessageFormatter.php

@@ -11,21 +11,29 @@
 
 namespace Symfony\Component\Translation\Formatter;
 
+use Symfony\Component\Translation\IdentityTranslator;
 use Symfony\Component\Translation\MessageSelector;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Abdellatif Ait boudad <a.aitboudad@gmail.com>
  */
 class MessageFormatter implements MessageFormatterInterface, ChoiceMessageFormatterInterface
 {
-    private $selector;
+    private $translator;
 
     /**
-     * @param MessageSelector|null $selector The message selector for pluralization
+     * @param TranslatorInterface|null $translator An identity translator to use as selector for pluralization
      */
-    public function __construct(MessageSelector $selector = null)
+    public function __construct($translator = null)
     {
-        $this->selector = $selector ?: new MessageSelector();
+        if ($translator instanceof MessageSelector) {
+            $translator = new IdentityTranslator($translator);
+        } elseif (null !== $translator && !$translator instanceof TranslatorInterface) {
+            throw new \TypeError(sprintf('Argument 1 passed to %s() must be an instance of %s, %s given.', __METHOD__, TranslatorInterface::class, \is_object($translator) ? \get_class($translator) : \gettype($translator)));
+        }
+
+        $this->translator = $translator ?? new IdentityTranslator();
     }
 
     /**
@@ -43,6 +51,6 @@ class MessageFormatter implements MessageFormatterInterface, ChoiceMessageFormat
     {
         $parameters = array_merge(array('%count%' => $number), $parameters);
 
-        return $this->format($this->selector->choose($message, (int) $number, $locale), $locale, $parameters);
+        return $this->format($this->translator->transChoice($message, $number, array(), null, $locale), $locale, $parameters);
     }
 }

src/Symfony/Component/Translation/IdentityTranslator.php

@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\Translation;
 
+use Symfony\Contracts\Translation\TranslatorTrait;
+
 /**
  * IdentityTranslator does not translate anything.
  *
@@ -18,39 +20,22 @@ namespace Symfony\Component\Translation;
  */
 class IdentityTranslator implements TranslatorInterface
 {
+    use TranslatorTrait {
+        transChoice as private doTransChoice;
+    }
+
     private $selector;
-    private $locale;
 
     /**
      * @param MessageSelector|null $selector The message selector for pluralization
      */
     public function __construct(MessageSelector $selector = null)
     {
-        $this->selector = $selector ?: new MessageSelector();
-    }
+        $this->selector = $selector;
 
-    /**
-     * {@inheritdoc}
-     */
-    public function setLocale($locale)
-    {
-        $this->locale = $locale;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getLocale()
-    {
-        return $this->locale ?: \Locale::getDefault();
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function trans($id, array $parameters = array(), $domain = null, $locale = null)
-    {
-        return strtr((string) $id, $parameters);
+        if (\get_class($this) !== __CLASS__) {
+            @trigger_error(sprintf('Calling "%s()" is deprecated since Symfony 4.2.'), E_USER_DEPRECATED);
+        }
     }
 
     /**
@@ -58,6 +43,15 @@ class IdentityTranslator implements TranslatorInterface
      */
     public function transChoice($id, $number, array $parameters = array(), $domain = null, $locale = null)
     {
-        return strtr($this->selector->choose((string) $id, (int) $number, $locale ?: $this->getLocale()), $parameters);
+        if ($this->selector) {
+            return strtr($this->selector->choose((string) $id, (int) $number, $locale ?: $this->getLocale()), $parameters);
+        }
+
+        return $this->doTransChoice($id, $number, $parameters, $domain, $locale);
+    }
+
+    private function getPluralizationRule(int $number, string $locale): int
+    {
+        return PluralizationRules::get($number, $locale, false);
     }
 }

src/Symfony/Component/Translation/Interval.php

@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\Translation;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.2, use IdentityTranslator instead.', Interval::class), E_USER_DEPRECATED);
+
 use Symfony\Component\Translation\Exception\InvalidArgumentException;
 
 /**
@@ -32,6 +34,7 @@ use Symfony\Component\Translation\Exception\InvalidArgumentException;
  * @author Fabien Potencier <fabien@symfony.com>
  *
  * @see    http://en.wikipedia.org/wiki/Interval_%28mathematics%29#The_ISO_notation
+ * @deprecated since Symfony 4.2, use IdentityTranslator instead
  */
 class Interval
 {

src/Symfony/Component/Translation/LoggingTranslator.php

@@ -13,11 +13,13 @@ namespace Symfony\Component\Translation;
 
 use Psr\Log\LoggerInterface;
 use Symfony\Component\Translation\Exception\InvalidArgumentException;
+use Symfony\Component\Translation\TranslatorInterface as LegacyTranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * @author Abdellatif Ait boudad <a.aitboudad@gmail.com>
  */
-class LoggingTranslator implements TranslatorInterface, TranslatorBagInterface
+class LoggingTranslator implements LegacyTranslatorInterface, TranslatorBagInterface
 {
     /**
      * @var TranslatorInterface|TranslatorBagInterface

src/Symfony/Component/Translation/MessageSelector.php

@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\Translation;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.2, use IdentityTranslator instead.', MessageSelector::class), E_USER_DEPRECATED);
+
 use Symfony\Component\Translation\Exception\InvalidArgumentException;
 
 /**
@@ -18,6 +20,8 @@ use Symfony\Component\Translation\Exception\InvalidArgumentException;
  *
  * @author Fabien Potencier <fabien@symfony.com>
  * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @deprecated since Symfony 4.2, use IdentityTranslator instead.
  */
 class MessageSelector
 {

src/Symfony/Component/Translation/PluralizationRules.php

@@ -15,6 +15,8 @@ namespace Symfony\Component\Translation;
  * Returns the plural rules for a given locale.
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @deprecated since Symfony 4.2, use IdentityTranslator instead
  */
 class PluralizationRules
 {
@@ -28,8 +30,12 @@ class PluralizationRules
      *
      * @return int The plural position
      */
-    public static function get($number, $locale)
+    public static function get($number, $locale/*, bool $triggerDeprecation = true*/)
     {
+        if (3 > \func_num_args() || \func_get_arg(2)) {
+            @trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.2.', __CLASS__), E_USER_DEPRECATED);
+        }
+
         if ('pt_BR' === $locale) {
             // temporary set a locale for brazilian
             $locale = 'xbr';
@@ -196,6 +202,8 @@ class PluralizationRules
      */
     public static function set(callable $rule, $locale)
     {
+        @trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.2.', __CLASS__), E_USER_DEPRECATED);
+
         if ('pt_BR' === $locale) {
             // temporary set a locale for brazilian
             $locale = 'xbr';

src/Symfony/Component/Translation/Tests/IdentityTranslatorTest.php

@@ -11,86 +11,13 @@
 
 namespace Symfony\Component\Translation\Tests;
 
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\Intl\Util\IntlTestHelper;
 use Symfony\Component\Translation\IdentityTranslator;
+use Symfony\Contracts\Tests\Translation\TranslatorTest;
 
-class IdentityTranslatorTest extends TestCase
+class IdentityTranslatorTest extends TranslatorTest
 {
-    /**
-     * @dataProvider getTransTests
-     */
-    public function testTrans($expected, $id, $parameters)
+    public function getTranslator()
     {
-        $translator = new IdentityTranslator();
-
-        $this->assertEquals($expected, $translator->trans($id, $parameters));
-    }
-
-    /**
-     * @dataProvider getTransChoiceTests
-     */
-    public function testTransChoiceWithExplicitLocale($expected, $id, $number, $parameters)
-    {
-        $translator = new IdentityTranslator();
-        $translator->setLocale('en');
-
-        $this->assertEquals($expected, $translator->transChoice($id, $number, $parameters));
-    }
-
-    /**
-     * @dataProvider getTransChoiceTests
-     */
-    public function testTransChoiceWithDefaultLocale($expected, $id, $number, $parameters)
-    {
-        \Locale::setDefault('en');
-
-        $translator = new IdentityTranslator();
-
-        $this->assertEquals($expected, $translator->transChoice($id, $number, $parameters));
-    }
-
-    public function testGetSetLocale()
-    {
-        $translator = new IdentityTranslator();
-        $translator->setLocale('en');
-
-        $this->assertEquals('en', $translator->getLocale());
-    }
-
-    public function testGetLocaleReturnsDefaultLocaleIfNotSet()
-    {
-        // in order to test with "pt_BR"
-        IntlTestHelper::requireFullIntl($this, false);
-
-        $translator = new IdentityTranslator();
-
-        \Locale::setDefault('en');
-        $this->assertEquals('en', $translator->getLocale());
-
-        \Locale::setDefault('pt_BR');
-        $this->assertEquals('pt_BR', $translator->getLocale());
-    }
-
-    public function getTransTests()
-    {
-        return array(
-            array('Symfony is great!', 'Symfony is great!', array()),
-            array('Symfony is awesome!', 'Symfony is %what%!', array('%what%' => 'awesome')),
-        );
-    }
-
-    public function getTransChoiceTests()
-    {
-        return array(
-            array('There are no apples', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 0, array('%count%' => 0)),
-            array('There is one apple', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 1, array('%count%' => 1)),
-            array('There are 10 apples', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 10, array('%count%' => 10)),
-            array('There are 0 apples', 'There is 1 apple|There are %count% apples', 0, array('%count%' => 0)),
-            array('There is 1 apple', 'There is 1 apple|There are %count% apples', 1, array('%count%' => 1)),
-            array('There are 10 apples', 'There is 1 apple|There are %count% apples', 10, array('%count%' => 10)),
-            // custom validation messages may be coded with a fixed value
-            array('There are 2 apples', 'There are 2 apples', 2, array('%count%' => 2)),
-        );
+        return new IdentityTranslator();
     }
 }

src/Symfony/Component/Translation/Tests/IntervalTest.php

@@ -14,6 +14,9 @@ namespace Symfony\Component\Translation\Tests;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Translation\Interval;
 
+/**
+ * @group legacy
+ */
 class IntervalTest extends TestCase
 {
     /**

src/Symfony/Component/Translation/Tests/MessageSelectorTest.php

@@ -14,6 +14,9 @@ namespace Symfony\Component\Translation\Tests;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Translation\MessageSelector;
 
+/**
+ * @group legacy
+ */
 class MessageSelectorTest extends TestCase
 {
     /**

src/Symfony/Component/Translation/Tests/PluralizationRulesTest.php

@@ -26,6 +26,8 @@ use Symfony\Component\Translation\PluralizationRules;
  * The goal to cover all languages is to far fetched so this test case is smaller.
  *
  * @author Clemens Tolboom clemens@build2be.nl
+ *
+ * @group legacy
  */
 class PluralizationRulesTest extends TestCase
 {

src/Symfony/Component/Translation/TranslatorInterface.php

@@ -11,57 +11,13 @@
 
 namespace Symfony\Component\Translation;
 
-use Symfony\Component\Translation\Exception\InvalidArgumentException;
+use Symfony\Contracts\Translation\TranslatorInterface as BaseTranslatorInterface;
 
 /**
- * TranslatorInterface.
- *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @deprecated since Symfony 4.2, use the same interface from the Symfony\Contracts\Translation namespace
  */
-interface TranslatorInterface
+interface TranslatorInterface extends BaseTranslatorInterface
 {
-    /**
-     * Translates the given message.
-     *
-     * @param string      $id         The message id (may also be an object that can be cast to string)
-     * @param array       $parameters An array of parameters for the message
-     * @param string|null $domain     The domain for the message or null to use the default
-     * @param string|null $locale     The locale or null to use the default
-     *
-     * @return string The translated string
-     *
-     * @throws InvalidArgumentException If the locale contains invalid characters
-     */
-    public function trans($id, array $parameters = array(), $domain = null, $locale = null);
-
-    /**
-     * Translates the given choice message by choosing a translation according to a number.
-     *
-     * @param string      $id         The message id (may also be an object that can be cast to string)
-     * @param int         $number     The number to use to find the indice of the message
-     * @param array       $parameters An array of parameters for the message
-     * @param string|null $domain     The domain for the message or null to use the default
-     * @param string|null $locale     The locale or null to use the default
-     *
-     * @return string The translated string
-     *
-     * @throws InvalidArgumentException If the locale contains invalid characters
-     */
-    public function transChoice($id, $number, array $parameters = array(), $domain = null, $locale = null);
-
-    /**
-     * Sets the current locale.
-     *
-     * @param string $locale The locale
-     *
-     * @throws InvalidArgumentException If the locale contains invalid characters
-     */
-    public function setLocale($locale);
-
-    /**
-     * Returns the current locale.
-     *
-     * @return string The locale
-     */
-    public function getLocale();
 }

src/Symfony/Component/Translation/composer.json

@@ -17,6 +17,7 @@
     ],
     "require": {
         "php": "^7.1.3",
+        "symfony/contracts": "^1.0",
         "symfony/polyfill-mbstring": "~1.0"
     },
     "require-dev": {

src/Symfony/Component/Validator/CHANGELOG.md

@@ -5,6 +5,9 @@ CHANGELOG
 -----
 
  * added `DivisibleBy` constraint
+ * decoupled from `symfony/translation` by using `Symfony\Contracts\Translation\TranslatorInterface`
+ * deprecated `ValidatorBuilderInterface`
+ * made `ValidatorBuilder` final
 
 4.1.0
 -----

src/Symfony/Component/Validator/Context/ExecutionContext.php

@@ -11,7 +11,6 @@
 
 namespace Symfony\Component\Validator\Context;
 
-use Symfony\Component\Translation\TranslatorInterface;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintViolation;
 use Symfony\Component\Validator\ConstraintViolationList;
@@ -22,6 +21,7 @@ use Symfony\Component\Validator\Mapping\PropertyMetadataInterface;
 use Symfony\Component\Validator\Util\PropertyPath;
 use Symfony\Component\Validator\Validator\ValidatorInterface;
 use Symfony\Component\Validator\Violation\ConstraintViolationBuilder;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * The context used and created by {@link ExecutionContextFactory}.

src/Symfony/Component/Validator/Context/ExecutionContextFactory.php

@@ -11,8 +11,8 @@
 
 namespace Symfony\Component\Validator\Context;
 
-use Symfony\Component\Translation\TranslatorInterface;
 use Symfony\Component\Validator\Validator\ValidatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * Creates new {@link ExecutionContext} instances.

src/Symfony/Component/Validator/DependencyInjection/AddValidatorInitializersPass.php

@@ -11,9 +11,13 @@
 
 namespace Symfony\Component\Validator\DependencyInjection;
 
+use Symfony\Component\DependencyInjection\ChildDefinition;
 use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\Translation\TranslatorInterface as LegacyTranslatorInterface;
+use Symfony\Component\Validator\Util\LegacyTranslatorProxy;
 
 /**
  * @author Fabien Potencier <fabien@symfony.com>
@@ -42,5 +46,27 @@ class AddValidatorInitializersPass implements CompilerPassInterface
         }
 
         $container->getDefinition($this->builderService)->addMethodCall('addObjectInitializers', array($initializers));
+
+        // @deprecated logic, to be removed in Symfony 5.0
+        $builder = $container->getDefinition($this->builderService);
+        $calls = [];
+
+        foreach ($builder->getMethodCalls() as list($method, $arguments)) {
+            if ('setTranslator' === $method) {
+                $translator = $arguments[0] instanceof Reference ? $container->findDefinition($arguments[0]) : $arguments[0];
+
+                while (!($class = $translator->getClass()) && $translator instanceof ChildDefinition) {
+                    $translator = $translator->getParent();
+                }
+
+                if (!is_subclass_of($class, LegacyTranslatorInterface::class)) {
+                    $arguments[0] = (new Definition(LegacyTranslatorProxy::class))->addArgument($arguments[0]);
+                }
+            }
+
+            $calls[] = array($method, $arguments);
+        }
+
+        $builder->setMethodCalls($calls);
     }
 }

src/Symfony/Component/Validator/Test/ConstraintValidatorTestCase.php

@@ -21,6 +21,7 @@ use Symfony\Component\Validator\Context\ExecutionContext;
 use Symfony\Component\Validator\Context\ExecutionContextInterface;
 use Symfony\Component\Validator\Mapping\ClassMetadata;
 use Symfony\Component\Validator\Mapping\PropertyMetadata;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * A test case to ease testing Constraint Validators.
@@ -95,7 +96,7 @@ abstract class ConstraintValidatorTestCase extends TestCase
 
     protected function createContext()
     {
-        $translator = $this->getMockBuilder('Symfony\Component\Translation\TranslatorInterface')->getMock();
+        $translator = $this->getMockBuilder(TranslatorInterface::class)->getMock();
         $validator = $this->getMockBuilder('Symfony\Component\Validator\Validator\ValidatorInterface')->getMock();
         $contextualValidator = $this->getMockBuilder('Symfony\Component\Validator\Validator\ContextualValidatorInterface')->getMock();
 

src/Symfony/Component/Validator/Tests/DependencyInjection/AddValidatorInitializersPassTest.php

@@ -13,8 +13,12 @@ namespace Symfony\Component\Validator\Tests\DependencyInjection;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\Validator\DependencyInjection\AddValidatorInitializersPass;
+use Symfony\Component\Validator\Util\LegacyTranslatorProxy;
+use Symfony\Contracts\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorTrait;
 
 class AddValidatorInitializersPassTest extends TestCase
 {
@@ -41,4 +45,34 @@ class AddValidatorInitializersPassTest extends TestCase
             $container->getDefinition('validator.builder')->getMethodCalls()
         );
     }
+
+    /**
+     * @group legacy
+     */
+    public function testLegacyTranslatorProxy()
+    {
+        $translator = new TestTranslator();
+        $proxy = new LegacyTranslatorProxy($translator);
+        $this->assertSame($translator, $proxy->getTranslator());
+
+        $container = new ContainerBuilder();
+        $container
+            ->register('validator.builder')
+            ->addMethodCall('setTranslator', array(new Reference('translator')))
+        ;
+
+        $container->register('translator', TestTranslator::class);
+
+        (new AddValidatorInitializersPass())->process($container);
+
+        $this->assertEquals(
+            array(array('setTranslator', array((new Definition(LegacyTranslatorProxy::class))->addArgument(new Reference('translator'))))),
+            $container->getDefinition('validator.builder')->removeMethodCall('addObjectInitializers')->getMethodCalls()
+        );
+    }
+}
+
+class TestTranslator implements TranslatorInterface
+{
+    use TranslatorTrait;
 }

src/Symfony/Component/Validator/Tests/ValidatorBuilderTest.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Validator\Tests;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Validator\Util\LegacyTranslatorProxy;
 use Symfony\Component\Validator\ValidatorBuilder;
 use Symfony\Component\Validator\ValidatorBuilderInterface;
 
@@ -105,6 +106,14 @@ class ValidatorBuilderTest extends TestCase
         );
     }
 
+    public function testLegacyTranslatorProxy()
+    {
+        $proxy = $this->getMockBuilder(LegacyTranslatorProxy::class)->disableOriginalConstructor()->getMock();
+        $proxy->expects($this->once())->method('getTranslator');
+
+        $this->builder->setTranslator($proxy);
+    }
+
     public function testSetTranslationDomain()
     {
         $this->assertSame($this->builder, $this->builder->setTranslationDomain('TRANS_DOMAIN'));

src/Symfony/Component/Validator/Util/LegacyTranslatorProxy.php

@@ -0,0 +1,65 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Validator\Util;
+
+use Symfony\Component\Translation\TranslatorInterface as LegacyTranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
+
+/**
+ * @internal to be removed in Symfony 5.0.
+ */
+class LegacyTranslatorProxy implements LegacyTranslatorInterface
+{
+    private $translator;
+
+    public function __construct(TranslatorInterface $translator)
+    {
+        $this->translator = $translator;
+    }
+
+    public function getTranslator(): TranslatorInterface
+    {
+        return $this->translator;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setLocale($locale)
+    {
+        $this->translator->setLocale($locale);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getLocale()
+    {
+        return $this->translator->getLocale();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function trans($id, array $parameters = array(), $domain = null, $locale = null)
+    {
+        return $this->translator->trans($id, $parameters, $domain, $locale);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function transChoice($id, $number, array $parameters = array(), $domain = null, $locale = null)
+    {
+        return $this->translator->transChoice($id, $number, $parameters, $domain, $locale);
+    }
+}

src/Symfony/Component/Validator/ValidatorBuilder.php

@@ -15,8 +15,7 @@ use Doctrine\Common\Annotations\AnnotationReader;
 use Doctrine\Common\Annotations\CachedReader;
 use Doctrine\Common\Annotations\Reader;
 use Doctrine\Common\Cache\ArrayCache;
-use Symfony\Component\Translation\IdentityTranslator;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Component\Translation\TranslatorInterface as LegacyTranslatorInterface;
 use Symfony\Component\Validator\Context\ExecutionContextFactory;
 use Symfony\Component\Validator\Exception\ValidatorException;
 use Symfony\Component\Validator\Mapping\Cache\CacheInterface;
@@ -28,16 +27,22 @@ use Symfony\Component\Validator\Mapping\Loader\LoaderInterface;
 use Symfony\Component\Validator\Mapping\Loader\StaticMethodLoader;
 use Symfony\Component\Validator\Mapping\Loader\XmlFileLoader;
 use Symfony\Component\Validator\Mapping\Loader\YamlFileLoader;
+use Symfony\Component\Validator\Util\LegacyTranslatorProxy;
 use Symfony\Component\Validator\Validator\RecursiveValidator;
+use Symfony\Contracts\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorTrait;
 
 /**
  * The default implementation of {@link ValidatorBuilderInterface}.
  *
  * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @final since Symfony 4.2
  */
 class ValidatorBuilder implements ValidatorBuilderInterface
 {
     private $initializers = array();
+    private $loaders = array();
     private $xmlMappings = array();
     private $yamlMappings = array();
     private $methodMappings = array();
@@ -249,9 +254,9 @@ class ValidatorBuilder implements ValidatorBuilderInterface
     /**
      * {@inheritdoc}
      */
-    public function setTranslator(TranslatorInterface $translator)
+    public function setTranslator(LegacyTranslatorInterface $translator)
     {
-        $this->translator = $translator;
+        $this->translator = $translator instanceof LegacyTranslatorProxy ? $translator->getTranslator() : $translator;
 
         return $this;
     }
@@ -266,6 +271,16 @@ class ValidatorBuilder implements ValidatorBuilderInterface
         return $this;
     }
 
+    /**
+     * @return $this
+     */
+    public function addLoader(LoaderInterface $loader)
+    {
+        $this->loaders[] = $loader;
+
+        return $this;
+    }
+
     /**
      * @return LoaderInterface[]
      */
@@ -289,7 +304,7 @@ class ValidatorBuilder implements ValidatorBuilderInterface
             $loaders[] = new AnnotationLoader($this->annotationReader);
         }
 
-        return $loaders;
+        return array_merge($loaders, $this->loaders);
     }
 
     /**
@@ -316,7 +331,9 @@ class ValidatorBuilder implements ValidatorBuilderInterface
         $translator = $this->translator;
 
         if (null === $translator) {
-            $translator = new IdentityTranslator();
+            $translator = new class() implements TranslatorInterface {
+                use TranslatorTrait;
+            };
             // Force the locale to be 'en' when no translator is provided rather than relying on the Intl default locale
             // This avoids depending on Intl or the stub implementation being available. It also ensures that Symfony
             // validation messages are pluralized properly even when the default locale gets changed because they are in

src/Symfony/Component/Validator/ValidatorBuilderInterface.php

@@ -21,6 +21,8 @@ use Symfony\Component\Validator\Validator\ValidatorInterface;
  * A configurable builder for ValidatorInterface objects.
  *
  * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @deprecated since Symfony 4.2, use the ValidatorBuilder class instead
  */
 interface ValidatorBuilderInterface
 {

src/Symfony/Component/Validator/Violation/ConstraintViolationBuilder.php

@@ -11,11 +11,11 @@
 
 namespace Symfony\Component\Validator\Violation;
 
-use Symfony\Component\Translation\TranslatorInterface;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintViolation;
 use Symfony\Component\Validator\ConstraintViolationList;
 use Symfony\Component\Validator\Util\PropertyPath;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
  * Default implementation of {@link ConstraintViolationBuilderInterface}.

src/Symfony/Component/Validator/Violation/ConstraintViolationBuilderInterface.php

@@ -64,7 +64,7 @@ interface ConstraintViolationBuilderInterface
      *
      * @return $this
      *
-     * @see \Symfony\Component\Translation\TranslatorInterface
+     * @see \Symfony\Contracts\Translation\TranslatorInterface
      */
     public function setTranslationDomain($translationDomain);
 
@@ -85,7 +85,7 @@ interface ConstraintViolationBuilderInterface
      *
      * @return $this
      *
-     * @see \Symfony\Component\Translation\TranslatorInterface::transChoice()
+     * @see \Symfony\Contracts\Translation\TranslatorInterface::transChoice()
      */
     public function setPlural($number);
 

src/Symfony/Component/Validator/composer.json

@@ -19,8 +19,7 @@
         "php": "^7.1.3",
         "symfony/contracts": "^1.0",
         "symfony/polyfill-ctype": "~1.8",
-        "symfony/polyfill-mbstring": "~1.0",
-        "symfony/translation": "~3.4|~4.0"
+        "symfony/polyfill-mbstring": "~1.0"
     },
     "require-dev": {
         "symfony/http-foundation": "~4.1",
@@ -33,6 +32,7 @@
         "symfony/expression-language": "~3.4|~4.0",
         "symfony/cache": "~3.4|~4.0",
         "symfony/property-access": "~3.4|~4.0",
+        "symfony/translation": "~4.2",
         "doctrine/annotations": "~1.0",
         "doctrine/cache": "~1.0",
         "egulias/email-validator": "^1.2.8|~2.0"
@@ -42,6 +42,7 @@
         "symfony/dependency-injection": "<3.4",
         "symfony/http-kernel": "<3.4",
         "symfony/intl": "<4.1",
+        "symfony/translation": "<4.2",
         "symfony/yaml": "<3.4"
     },
     "suggest": {
@@ -50,6 +51,7 @@
         "doctrine/cache": "For using the default cached annotation reader and metadata cache.",
         "symfony/http-foundation": "",
         "symfony/intl": "",
+        "symfony/translation": "For translating validation errors.",
         "symfony/yaml": "",
         "symfony/config": "",
         "egulias/email-validator": "Strict (RFC compliant) email validation",

src/Symfony/Contracts/CHANGELOG.md

@@ -5,3 +5,4 @@ CHANGELOG
 -----
 
  * added `Service\ResetInterface` to provide a way to reset an object to its initial state
+ * added `Translation\TranslatorInterface` and `Translation\TranslatorTrait`

src/Symfony/Contracts/Tests/Translation/TranslatorTest.php

@@ -0,0 +1,353 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Contracts\Tests\Translation;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Contracts\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorTrait;
+
+/**
+ * Test should cover all languages mentioned on http://translate.sourceforge.net/wiki/l10n/pluralforms
+ * and Plural forms mentioned on http://www.gnu.org/software/gettext/manual/gettext.html#Plural-forms.
+ *
+ * See also https://developer.mozilla.org/en/Localization_and_Plurals which mentions 15 rules having a maximum of 6 forms.
+ * The mozilla code is also interesting to check for.
+ *
+ * As mentioned by chx http://drupal.org/node/1273968 we can cover all by testing number from 0 to 199
+ *
+ * The goal to cover all languages is to far fetched so this test case is smaller.
+ *
+ * @author Clemens Tolboom clemens@build2be.nl
+ */
+class TranslatorTest extends TestCase
+{
+    public function getTranslator()
+    {
+        return new class() implements TranslatorInterface {
+            use TranslatorTrait;
+        };
+    }
+
+    /**
+     * @dataProvider getTransTests
+     */
+    public function testTrans($expected, $id, $parameters)
+    {
+        $translator = $this->getTranslator();
+
+        $this->assertEquals($expected, $translator->trans($id, $parameters));
+    }
+
+    /**
+     * @dataProvider getTransChoiceTests
+     */
+    public function testTransChoiceWithExplicitLocale($expected, $id, $number, $parameters)
+    {
+        $translator = $this->getTranslator();
+        $translator->setLocale('en');
+
+        $this->assertEquals($expected, $translator->transChoice($id, $number, $parameters));
+    }
+
+    /**
+     * @dataProvider getTransChoiceTests
+     */
+    public function testTransChoiceWithDefaultLocale($expected, $id, $number, $parameters)
+    {
+        \Locale::setDefault('en');
+
+        $translator = $this->getTranslator();
+
+        $this->assertEquals($expected, $translator->transChoice($id, $number, $parameters));
+    }
+
+    public function testGetSetLocale()
+    {
+        $translator = $this->getTranslator();
+        $translator->setLocale('en');
+
+        $this->assertEquals('en', $translator->getLocale());
+    }
+
+    /**
+     * @requires extension intl
+     */
+    public function testGetLocaleReturnsDefaultLocaleIfNotSet()
+    {
+        $translator = $this->getTranslator();
+
+        \Locale::setDefault('pt_BR');
+        $this->assertEquals('pt_BR', $translator->getLocale());
+
+        \Locale::setDefault('en');
+        $this->assertEquals('en', $translator->getLocale());
+    }
+
+    public function getTransTests()
+    {
+        return array(
+            array('Symfony is great!', 'Symfony is great!', array()),
+            array('Symfony is awesome!', 'Symfony is %what%!', array('%what%' => 'awesome')),
+        );
+    }
+
+    public function getTransChoiceTests()
+    {
+        return array(
+            array('There are no apples', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 0, array('%count%' => 0)),
+            array('There is one apple', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 1, array('%count%' => 1)),
+            array('There are 10 apples', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 10, array('%count%' => 10)),
+            array('There are 0 apples', 'There is 1 apple|There are %count% apples', 0, array('%count%' => 0)),
+            array('There is 1 apple', 'There is 1 apple|There are %count% apples', 1, array('%count%' => 1)),
+            array('There are 10 apples', 'There is 1 apple|There are %count% apples', 10, array('%count%' => 10)),
+            // custom validation messages may be coded with a fixed value
+            array('There are 2 apples', 'There are 2 apples', 2, array('%count%' => 2)),
+        );
+    }
+
+    /**
+     * @dataProvider getInternal
+     */
+    public function testInterval($expected, $number, $interval)
+    {
+        $translator = $this->getTranslator();
+
+        $this->assertEquals($expected, $translator->transChoice($interval.' foo|[1,Inf[ bar', $number));
+    }
+
+    public function getInternal()
+    {
+        return array(
+            array('foo', 3, '{1,2, 3 ,4}'),
+            array('bar', 10, '{1,2, 3 ,4}'),
+            array('bar', 3, '[1,2]'),
+            array('foo', 1, '[1,2]'),
+            array('foo', 2, '[1,2]'),
+            array('bar', 1, ']1,2['),
+            array('bar', 2, ']1,2['),
+            array('foo', log(0), '[-Inf,2['),
+            array('foo', -log(0), '[-2,+Inf]'),
+        );
+    }
+
+    /**
+     * @dataProvider getChooseTests
+     */
+    public function testChoose($expected, $id, $number)
+    {
+        $translator = $this->getTranslator();
+
+        $this->assertEquals($expected, $translator->transChoice($id, $number));
+    }
+
+    public function testReturnMessageIfExactlyOneStandardRuleIsGiven()
+    {
+        $translator = $this->getTranslator();
+
+        $this->assertEquals('There are two apples', $translator->transChoice('There are two apples', 2));
+    }
+
+    /**
+     * @dataProvider getNonMatchingMessages
+     * @expectedException \InvalidArgumentException
+     */
+    public function testThrowExceptionIfMatchingMessageCannotBeFound($id, $number)
+    {
+        $translator = $this->getTranslator();
+
+        $translator->transChoice($id, $number);
+    }
+
+    public function getNonMatchingMessages()
+    {
+        return array(
+            array('{0} There are no apples|{1} There is one apple', 2),
+            array('{1} There is one apple|]1,Inf] There are %count% apples', 0),
+            array('{1} There is one apple|]2,Inf] There are %count% apples', 2),
+            array('{0} There are no apples|There is one apple', 2),
+        );
+    }
+
+    public function getChooseTests()
+    {
+        return array(
+            array('There are no apples', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 0),
+            array('There are no apples', '{0}     There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 0),
+            array('There are no apples', '{0}There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 0),
+
+            array('There is one apple', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 1),
+
+            array('There are %count% apples', '{0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples', 10),
+            array('There are %count% apples', '{0} There are no apples|{1} There is one apple|]1,Inf]There are %count% apples', 10),
+            array('There are %count% apples', '{0} There are no apples|{1} There is one apple|]1,Inf]     There are %count% apples', 10),
+
+            array('There are %count% apples', 'There is one apple|There are %count% apples', 0),
+            array('There is one apple', 'There is one apple|There are %count% apples', 1),
+            array('There are %count% apples', 'There is one apple|There are %count% apples', 10),
+
+            array('There are %count% apples', 'one: There is one apple|more: There are %count% apples', 0),
+            array('There is one apple', 'one: There is one apple|more: There are %count% apples', 1),
+            array('There are %count% apples', 'one: There is one apple|more: There are %count% apples', 10),
+
+            array('There are no apples', '{0} There are no apples|one: There is one apple|more: There are %count% apples', 0),
+            array('There is one apple', '{0} There are no apples|one: There is one apple|more: There are %count% apples', 1),
+            array('There are %count% apples', '{0} There are no apples|one: There is one apple|more: There are %count% apples', 10),
+
+            array('', '{0}|{1} There is one apple|]1,Inf] There are %count% apples', 0),
+            array('', '{0} There are no apples|{1}|]1,Inf] There are %count% apples', 1),
+
+            // Indexed only tests which are Gettext PoFile* compatible strings.
+            array('There are %count% apples', 'There is one apple|There are %count% apples', 0),
+            array('There is one apple', 'There is one apple|There are %count% apples', 1),
+            array('There are %count% apples', 'There is one apple|There are %count% apples', 2),
+
+            // Tests for float numbers
+            array('There is almost one apple', '{0} There are no apples|]0,1[ There is almost one apple|{1} There is one apple|[1,Inf] There is more than one apple', 0.7),
+            array('There is one apple', '{0} There are no apples|]0,1[There are %count% apples|{1} There is one apple|[1,Inf] There is more than one apple', 1),
+            array('There is more than one apple', '{0} There are no apples|]0,1[There are %count% apples|{1} There is one apple|[1,Inf] There is more than one apple', 1.7),
+            array('There are no apples', '{0} There are no apples|]0,1[There are %count% apples|{1} There is one apple|[1,Inf] There is more than one apple', 0),
+            array('There are no apples', '{0} There are no apples|]0,1[There are %count% apples|{1} There is one apple|[1,Inf] There is more than one apple', 0.0),
+            array('There are no apples', '{0.0} There are no apples|]0,1[There are %count% apples|{1} There is one apple|[1,Inf] There is more than one apple', 0),
+
+            // Test texts with new-lines
+            // with double-quotes and \n in id & double-quotes and actual newlines in text
+            array("This is a text with a\n            new-line in it. Selector = 0.", '{0}This is a text with a
+            new-line in it. Selector = 0.|{1}This is a text with a
+            new-line in it. Selector = 1.|[1,Inf]This is a text with a
+            new-line in it. Selector > 1.', 0),
+            // with double-quotes and \n in id and single-quotes and actual newlines in text
+            array("This is a text with a\n            new-line in it. Selector = 1.", '{0}This is a text with a
+            new-line in it. Selector = 0.|{1}This is a text with a
+            new-line in it. Selector = 1.|[1,Inf]This is a text with a
+            new-line in it. Selector > 1.', 1),
+            array("This is a text with a\n            new-line in it. Selector > 1.", '{0}This is a text with a
+            new-line in it. Selector = 0.|{1}This is a text with a
+            new-line in it. Selector = 1.|[1,Inf]This is a text with a
+            new-line in it. Selector > 1.', 5),
+            // with double-quotes and id split accros lines
+            array('This is a text with a
+            new-line in it. Selector = 1.', '{0}This is a text with a
+            new-line in it. Selector = 0.|{1}This is a text with a
+            new-line in it. Selector = 1.|[1,Inf]This is a text with a
+            new-line in it. Selector > 1.', 1),
+            // with single-quotes and id split accros lines
+            array('This is a text with a
+            new-line in it. Selector > 1.', '{0}This is a text with a
+            new-line in it. Selector = 0.|{1}This is a text with a
+            new-line in it. Selector = 1.|[1,Inf]This is a text with a
+            new-line in it. Selector > 1.', 5),
+            // with single-quotes and \n in text
+            array('This is a text with a\nnew-line in it. Selector = 0.', '{0}This is a text with a\nnew-line in it. Selector = 0.|{1}This is a text with a\nnew-line in it. Selector = 1.|[1,Inf]This is a text with a\nnew-line in it. Selector > 1.', 0),
+            // with double-quotes and id split accros lines
+            array("This is a text with a\nnew-line in it. Selector = 1.", "{0}This is a text with a\nnew-line in it. Selector = 0.|{1}This is a text with a\nnew-line in it. Selector = 1.|[1,Inf]This is a text with a\nnew-line in it. Selector > 1.", 1),
+            // esacape pipe
+            array('This is a text with | in it. Selector = 0.', '{0}This is a text with || in it. Selector = 0.|{1}This is a text with || in it. Selector = 1.', 0),
+            // Empty plural set (2 plural forms) from a .PO file
+            array('', '|', 1),
+            // Empty plural set (3 plural forms) from a .PO file
+            array('', '||', 1),
+        );
+    }
+
+    /**
+     * @dataProvider failingLangcodes
+     */
+    public function testFailedLangcodes($nplural, $langCodes)
+    {
+        $matrix = $this->generateTestData($langCodes);
+        $this->validateMatrix($nplural, $matrix, false);
+    }
+
+    /**
+     * @dataProvider successLangcodes
+     */
+    public function testLangcodes($nplural, $langCodes)
+    {
+        $matrix = $this->generateTestData($langCodes);
+        $this->validateMatrix($nplural, $matrix);
+    }
+
+    /**
+     * This array should contain all currently known langcodes.
+     *
+     * As it is impossible to have this ever complete we should try as hard as possible to have it almost complete.
+     *
+     * @return array
+     */
+    public function successLangcodes()
+    {
+        return array(
+            array('1', array('ay', 'bo', 'cgg', 'dz', 'id', 'ja', 'jbo', 'ka', 'kk', 'km', 'ko', 'ky')),
+            array('2', array('nl', 'fr', 'en', 'de', 'de_GE', 'hy', 'hy_AM')),
+            array('3', array('be', 'bs', 'cs', 'hr')),
+            array('4', array('cy', 'mt', 'sl')),
+            array('6', array('ar')),
+        );
+    }
+
+    /**
+     * This array should be at least empty within the near future.
+     *
+     * This both depends on a complete list trying to add above as understanding
+     * the plural rules of the current failing languages.
+     *
+     * @return array with nplural together with langcodes
+     */
+    public function failingLangcodes()
+    {
+        return array(
+            array('1', array('fa')),
+            array('2', array('jbo')),
+            array('3', array('cbs')),
+            array('4', array('gd', 'kw')),
+            array('5', array('ga')),
+        );
+    }
+
+    /**
+     * We validate only on the plural coverage. Thus the real rules is not tested.
+     *
+     * @param string $nplural       Plural expected
+     * @param array  $matrix        Containing langcodes and their plural index values
+     * @param bool   $expectSuccess
+     */
+    protected function validateMatrix($nplural, $matrix, $expectSuccess = true)
+    {
+        foreach ($matrix as $langCode => $data) {
+            $indexes = array_flip($data);
+            if ($expectSuccess) {
+                $this->assertEquals($nplural, \count($indexes), "Langcode '$langCode' has '$nplural' plural forms.");
+            } else {
+                $this->assertNotEquals((int) $nplural, \count($indexes), "Langcode '$langCode' has '$nplural' plural forms.");
+            }
+        }
+    }
+
+    protected function generateTestData($langCodes)
+    {
+        $translator = new class() {
+            use TranslatorTrait {
+                getPluralizationRule as public;
+            }
+        };
+
+        $matrix = array();
+        foreach ($langCodes as $langCode) {
+            for ($count = 0; $count < 200; ++$count) {
+                $plural = $translator->getPluralizationRule($count, $langCode);
+                $matrix[$langCode][$count] = $plural;
+            }
+        }
+
+        return $matrix;
+    }
+}

src/Symfony/Contracts/Translation/TranslatorInterface.php

@@ -0,0 +1,93 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Contracts\Translation;
+
+/**
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+interface TranslatorInterface
+{
+    /**
+     * Translates the given message.
+     *
+     * @param string      $id         The message id (may also be an object that can be cast to string)
+     * @param array       $parameters An array of parameters for the message
+     * @param string|null $domain     The domain for the message or null to use the default
+     * @param string|null $locale     The locale or null to use the default
+     *
+     * @return string The translated string
+     *
+     * @throws \InvalidArgumentException If the locale contains invalid characters
+     */
+    public function trans($id, array $parameters = array(), $domain = null, $locale = null);
+
+    /**
+     * Translates the given choice message by choosing a translation according to a number.
+     *
+     * Given a message with different plural translations separated by a
+     * pipe (|), this method returns the correct portion of the message based
+     * on the given number, locale and the pluralization rules in the message
+     * itself.
+     *
+     * The message supports two different types of pluralization rules:
+     *
+     * interval: {0} There are no apples|{1} There is one apple|]1,Inf] There are %count% apples
+     * indexed:  There is one apple|There are %count% apples
+     *
+     * The indexed solution can also contain labels (e.g. one: There is one apple).
+     * This is purely for making the translations more clear - it does not
+     * affect the functionality.
+     *
+     * The two methods can also be mixed:
+     *     {0} There are no apples|one: There is one apple|more: There are %count% apples
+     *
+     * An interval can represent a finite set of numbers:
+     *  {1,2,3,4}
+     *
+     * An interval can represent numbers between two numbers:
+     *  [1, +Inf]
+     *  ]-1,2[
+     *
+     * The left delimiter can be [ (inclusive) or ] (exclusive).
+     * The right delimiter can be [ (exclusive) or ] (inclusive).
+     * Beside numbers, you can use -Inf and +Inf for the infinite.
+     *
+     * @see https://en.wikipedia.org/wiki/ISO_31-11
+     *
+     * @param string      $id         The message id (may also be an object that can be cast to string)
+     * @param int         $number     The number to use to find the indice of the message
+     * @param array       $parameters An array of parameters for the message
+     * @param string|null $domain     The domain for the message or null to use the default
+     * @param string|null $locale     The locale or null to use the default
+     *
+     * @return string The translated string
+     *
+     * @throws \InvalidArgumentException If the locale contains invalid characters
+     */
+    public function transChoice($id, $number, array $parameters = array(), $domain = null, $locale = null);
+
+    /**
+     * Sets the current locale.
+     *
+     * @param string $locale The locale
+     *
+     * @throws \InvalidArgumentException If the locale contains invalid characters
+     */
+    public function setLocale($locale);
+
+    /**
+     * Returns the current locale.
+     *
+     * @return string The locale
+     */
+    public function getLocale();
+}

src/Symfony/Contracts/Translation/TranslatorTrait.php

@@ -0,0 +1,258 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Contracts\Translation;
+
+use Symfony\Component\Translation\Exception\InvalidArgumentException;
+
+/**
+ * A trait to help implement TranslatorInterface.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+trait TranslatorTrait
+{
+    private $locale;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setLocale($locale)
+    {
+        $this->locale = (string) $locale;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getLocale()
+    {
+        return $this->locale ?: \Locale::getDefault();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function trans($id, array $parameters = array(), $domain = null, $locale = null)
+    {
+        return strtr((string) $id, $parameters);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function transChoice($id, $number, array $parameters = array(), $domain = null, $locale = null)
+    {
+        $id = (string) $id;
+        $number = (float) $number;
+        $locale = (string) $locale ?: $this->getLocale();
+
+        $parts = array();
+        if (preg_match('/^\|++$/', $id)) {
+            $parts = explode('|', $id);
+        } elseif (preg_match_all('/(?:\|\||[^\|])++/', $id, $matches)) {
+            $parts = $matches[0];
+        }
+
+        $intervalRegexp = <<<'EOF'
+/^(?P<interval>
+    ({\s*
+        (\-?\d+(\.\d+)?[\s*,\s*\-?\d+(\.\d+)?]*)
+    \s*})
+
+        |
+
+    (?P<left_delimiter>[\[\]])
+        \s*
+        (?P<left>-Inf|\-?\d+(\.\d+)?)
+        \s*,\s*
+        (?P<right>\+?Inf|\-?\d+(\.\d+)?)
+        \s*
+    (?P<right_delimiter>[\[\]])
+)\s*(?P<message>.*?)$/xs
+EOF;
+
+        $standardRules = array();
+        foreach ($parts as $part) {
+            $part = trim(str_replace('||', '|', $part));
+
+            // try to match an explicit rule, then fallback to the standard ones
+            if (preg_match($intervalRegexp, $part, $matches)) {
+                if ($matches[2]) {
+                    foreach (explode(',', $matches[3]) as $n) {
+                        if ($number == $n) {
+                            return strtr($matches['message'], $parameters);
+                        }
+                    }
+                } else {
+                    $leftNumber = '-Inf' === $matches['left'] ? -INF : (float) $matches['left'];
+                    $rightNumber = \is_numeric($matches['right']) ? (float) $matches['right'] : INF;
+
+                    if (('[' === $matches['left_delimiter'] ? $number >= $leftNumber : $number > $leftNumber)
+                        && (']' === $matches['right_delimiter'] ? $number <= $rightNumber : $number < $rightNumber)
+                    ) {
+                        return strtr($matches['message'], $parameters);
+                    }
+                }
+            } elseif (preg_match('/^\w+\:\s*(.*?)$/', $part, $matches)) {
+                $standardRules[] = $matches[1];
+            } else {
+                $standardRules[] = $part;
+            }
+        }
+
+        $position = $this->getPluralizationRule($number, $locale);
+
+        if (!isset($standardRules[$position])) {
+            // when there's exactly one rule given, and that rule is a standard
+            // rule, use this rule
+            if (1 === \count($parts) && isset($standardRules[0])) {
+                return strtr($standardRules[0], $parameters);
+            }
+
+            $message = sprintf('Unable to choose a translation for "%s" with locale "%s" for value "%d". Double check that this translation has the correct plural options (e.g. "There is one apple|There are %%count%% apples").', $id, $locale, $number);
+
+            if (\class_exists(InvalidArgumentException::class)) {
+                throw new InvalidArgumentException($message);
+            }
+
+            throw new \InvalidArgumentException($message);
+        }
+
+        return strtr($standardRules[$position], $parameters);
+    }
+
+    /**
+     * Returns the plural position to use for the given locale and number.
+     *
+     * The plural rules are derived from code of the Zend Framework (2010-09-25),
+     * which is subject to the new BSD license (http://framework.zend.com/license/new-bsd).
+     * Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+     */
+    private function getPluralizationRule(int $number, string $locale): int
+    {
+        switch ('pt_BR' !== $locale && \strlen($locale) > 3 ? substr($locale, 0, strrpos($locale, '_')) : $locale) {
+            case 'af':
+            case 'bn':
+            case 'bg':
+            case 'ca':
+            case 'da':
+            case 'de':
+            case 'el':
+            case 'en':
+            case 'eo':
+            case 'es':
+            case 'et':
+            case 'eu':
+            case 'fa':
+            case 'fi':
+            case 'fo':
+            case 'fur':
+            case 'fy':
+            case 'gl':
+            case 'gu':
+            case 'ha':
+            case 'he':
+            case 'hu':
+            case 'is':
+            case 'it':
+            case 'ku':
+            case 'lb':
+            case 'ml':
+            case 'mn':
+            case 'mr':
+            case 'nah':
+            case 'nb':
+            case 'ne':
+            case 'nl':
+            case 'nn':
+            case 'no':
+            case 'oc':
+            case 'om':
+            case 'or':
+            case 'pa':
+            case 'pap':
+            case 'ps':
+            case 'pt':
+            case 'so':
+            case 'sq':
+            case 'sv':
+            case 'sw':
+            case 'ta':
+            case 'te':
+            case 'tk':
+            case 'ur':
+            case 'zu':
+                return (1 == $number) ? 0 : 1;
+
+            case 'am':
+            case 'bh':
+            case 'fil':
+            case 'fr':
+            case 'gun':
+            case 'hi':
+            case 'hy':
+            case 'ln':
+            case 'mg':
+            case 'nso':
+            case 'pt_BR':
+            case 'ti':
+            case 'wa':
+                return ((0 == $number) || (1 == $number)) ? 0 : 1;
+
+            case 'be':
+            case 'bs':
+            case 'hr':
+            case 'ru':
+            case 'sh':
+            case 'sr':
+            case 'uk':
+                return ((1 == $number % 10) && (11 != $number % 100)) ? 0 : ((($number % 10 >= 2) && ($number % 10 <= 4) && (($number % 100 < 10) || ($number % 100 >= 20))) ? 1 : 2);
+
+            case 'cs':
+            case 'sk':
+                return (1 == $number) ? 0 : ((($number >= 2) && ($number <= 4)) ? 1 : 2);
+
+            case 'ga':
+                return (1 == $number) ? 0 : ((2 == $number) ? 1 : 2);
+
+            case 'lt':
+                return ((1 == $number % 10) && (11 != $number % 100)) ? 0 : ((($number % 10 >= 2) && (($number % 100 < 10) || ($number % 100 >= 20))) ? 1 : 2);
+
+            case 'sl':
+                return (1 == $number % 100) ? 0 : ((2 == $number % 100) ? 1 : (((3 == $number % 100) || (4 == $number % 100)) ? 2 : 3));
+
+            case 'mk':
+                return (1 == $number % 10) ? 0 : 1;
+
+            case 'mt':
+                return (1 == $number) ? 0 : (((0 == $number) || (($number % 100 > 1) && ($number % 100 < 11))) ? 1 : ((($number % 100 > 10) && ($number % 100 < 20)) ? 2 : 3));
+
+            case 'lv':
+                return (0 == $number) ? 0 : (((1 == $number % 10) && (11 != $number % 100)) ? 1 : 2);
+
+            case 'pl':
+                return (1 == $number) ? 0 : ((($number % 10 >= 2) && ($number % 10 <= 4) && (($number % 100 < 12) || ($number % 100 > 14))) ? 1 : 2);
+
+            case 'cy':
+                return (1 == $number) ? 0 : ((2 == $number) ? 1 : (((8 == $number) || (11 == $number)) ? 2 : 3));
+
+            case 'ro':
+                return (1 == $number) ? 0 : (((0 == $number) || (($number % 100 > 0) && ($number % 100 < 20))) ? 1 : 2);
+
+            case 'ar':
+                return (0 == $number) ? 0 : ((1 == $number) ? 1 : ((2 == $number) ? 2 : ((($number % 100 >= 3) && ($number % 100 <= 10)) ? 3 : ((($number % 100 >= 11) && ($number % 100 <= 99)) ? 4 : 5))));
+
+            default:
+                return 0;
+        }
+    }
+}