feature #25504 [Validator] Add option to pass custom values to Expression validator (ostrolucky)

This PR was merged into the 4.1-dev branch.

Discussion
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[Validator] Add option to pass custom values to Expression validator

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

I needed this in a Form. I had no way to pass things from `$options` into Expression validator.

Maybe can aid in https://github.com/symfony/symfony/pull/23134

Commits
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ba0565e3e8 [Validator] Add option to pass custom values to Expression validator

src/Symfony/Component/Validator/CHANGELOG.md

@@ -5,6 +5,7 @@ CHANGELOG
 -----
 
  * Deprecated the `checkDNS` and `dnsMessage` options of the `Url` constraint. They will be removed in 5.0.
+ * added a `values` option to the `Expression` constraint
 
 4.0.0
 -----

src/Symfony/Component/Validator/Constraints/Expression.php

@@ -30,6 +30,7 @@ class Expression extends Constraint
 
     public $message = 'This value is not valid.';
     public $expression;
+    public $values = array();
 
     /**
      * {@inheritdoc}

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

@@ -39,7 +39,7 @@ class ExpressionValidator extends ConstraintValidator
             throw new UnexpectedTypeException($constraint, __NAMESPACE__.'\Expression');
         }
 
-        $variables = array();
+        $variables = $constraint->values;
         $variables['value'] = $value;
         $variables['this'] = $this->context->getObject();
 

src/Symfony/Component/Validator/Tests/Constraints/ExpressionValidatorTest.php

@@ -270,4 +270,18 @@ class ExpressionValidatorTest extends ConstraintValidatorTestCase
 
         $this->assertTrue($used, 'Failed asserting that custom ExpressionLanguage instance is used.');
     }
+
+    public function testPassingCustomValues()
+    {
+        $constraint = new Expression(array(
+            'expression' => 'value + custom == 2',
+            'values' => array(
+                'custom' => 1,
+            ),
+        ));
+
+        $this->validator->validate(1, $constraint);
+
+        $this->assertNoViolation();
+    }
 }