[Validator] deprecate checkMX and checkHost on Email validator

Author: fabpot

Constraints/Email.php

@@ -28,7 +28,15 @@ class Email extends Constraint
     public const VALIDATION_MODE_LOOSE = 'loose';
 
     const INVALID_FORMAT_ERROR = 'bd79c0ab-ddba-46cc-a703-a7a4b08de310';
+
+    /**
+     * @deprecated since Symfony 4.2.
+     */
     const MX_CHECK_FAILED_ERROR = 'bf447c1c-0266-4e10-9c6c-573df282e413';
+
+    /**
+     * @deprecated since Symfony 4.2.
+     */
     const HOST_CHECK_FAILED_ERROR = '7da53a8b-56f3-4288-bb3e-ee9ede4ef9a1';
 
     protected static $errorNames = array(
@@ -49,11 +57,19 @@ class Email extends Constraint
     );
 
     public $message = 'This value is not a valid email address.';
+
+    /**
+     * @deprecated since Symfony 4.2.
+     */
     public $checkMX = false;
+
+    /**
+     * @deprecated since Symfony 4.2.
+     */
     public $checkHost = false;
 
     /**
-     * @deprecated since Symfony 4.1. Set mode to "strict" instead.
+     * @deprecated since Symfony 4.1, set mode to "strict" instead.
      */
     public $strict;
     public $mode;
@@ -64,6 +80,14 @@ public function __construct($options = null)
             @trigger_error(sprintf('The "strict" property is deprecated since Symfony 4.1. Use "mode"=>"%s" instead.', self::VALIDATION_MODE_STRICT), E_USER_DEPRECATED);
         }
 
+        if (\is_array($options) && array_key_exists('checkMX', $options)) {
+            @trigger_error('The "checkMX" property is deprecated since Symfony 4.2.', E_USER_DEPRECATED);
+        }
+
+        if (\is_array($options) && array_key_exists('checkHost', $options)) {
+            @trigger_error('The "checkHost" property is deprecated since Symfony 4.2.', E_USER_DEPRECATED);
+        }
+
         if (\is_array($options) && array_key_exists('mode', $options) && !\in_array($options['mode'], self::$validationModes, true)) {
             throw new \InvalidArgumentException('The "mode" parameter value is not valid.');
         }

Tests/Constraints/EmailValidatorTest.php

@@ -317,6 +317,7 @@ public function getInvalidEmailsForStrictChecks()
     /**
      * @dataProvider getDnsChecks
      * @requires function Symfony\Bridge\PhpUnit\DnsMock::withMockedHosts
+     * @group legacy
      */
     public function testDnsChecks($type, $violation)
     {
@@ -353,6 +354,7 @@ public function getDnsChecks()
 
     /**
      * @requires function Symfony\Bridge\PhpUnit\DnsMock::withMockedHosts
+     * @group legacy
      */
     public function testHostnameIsProperlyParsed()
     {
@@ -368,6 +370,7 @@ public function testHostnameIsProperlyParsed()
 
     /**
      * @dataProvider provideCheckTypes
+     * @group legacy
      */
     public function testEmptyHostIsNotValid($checkType, $violation)
     {