symfony · mpiot · May 20, 2021 · May 25, 2021 · Jun 28, 2021 · Jun 29, 2021
diff --git a/src/Symfony/Component/Validator/Constraints/ExpressionLanguageSyntax.php b/src/Symfony/Component/Validator/Constraints/ExpressionLanguageSyntax.php
@@ -31,14 +31,20 @@ class ExpressionLanguageSyntax extends Constraint
    public $message = 'This value should be a valid expression.';
    public $service;
    public $allowedVariables;
+    public $allowNullAndEmptyString = false;

-    public function __construct(array $options = null, string $message = null, string $service = null, array $allowedVariables = null, array $groups = null, $payload = null)
+    public function __construct(array $options = null, string $message = null, string $service = null, array $allowedVariables = null, bool $allowNullAndEmptyString = null, array $groups = null, $payload = null)
    {
        parent::__construct($options, $groups, $payload);

        $this->message = $message ?? $this->message;
        $this->service = $service ?? $this->service;
        $this->allowedVariables = $allowedVariables ?? $this->allowedVariables;
+        $this->allowNullAndEmptyString = $allowNullAndEmptyString ?? $this->allowNullAndEmptyString;
+
+        if (!$this->allowNullAndEmptyString) {
+            trigger_deprecation('symfony/validator', '5.4', 'Validating empty expressions with "%s" constraint is deprecated. Set "allowNullAndEmptyString" option to "true" instead and add explicit constraint like NotNull or NotBlank.', __CLASS__);
+        }
    }

    /**

diff --git a/src/Symfony/Component/Validator/Constraints/ExpressionLanguageSyntaxValidator.php b/src/Symfony/Component/Validator/Constraints/ExpressionLanguageSyntaxValidator.php
@@ -39,6 +39,10 @@ public function validate($expression, Constraint $constraint): void
            throw new UnexpectedTypeException($constraint, ExpressionLanguageSyntax::class);
        }

+        if (true === $constraint->allowNullAndEmptyString && (null === $expression || '' === $expression)) {
+            return;
+        }
+
        if (!\is_string($expression)) {
            throw new UnexpectedValueException($expression, 'string');
        }

diff --git a/src/Symfony/Component/Validator/Tests/Constraints/ExpressionLanguageSyntaxTest.php b/src/Symfony/Component/Validator/Tests/Constraints/ExpressionLanguageSyntaxTest.php
@@ -61,6 +61,7 @@ public function testAttributes()
        [$aConstraint] = $metadata->properties['a']->getConstraints();
        self::assertNull($aConstraint->service);
        self::assertNull($aConstraint->allowedVariables);
+        self::assertFalse($aConstraint->allowNullAndEmptyString);

        [$bConstraint] = $metadata->properties['b']->getConstraints();
        self::assertSame('my_service', $bConstraint->service);
@@ -70,6 +71,9 @@ public function testAttributes()
        [$cConstraint] = $metadata->properties['c']->getConstraints();
        self::assertSame(['foo', 'bar'], $cConstraint->allowedVariables);
        self::assertSame(['my_group'], $cConstraint->groups);
+
+        [$dConstraint] = $metadata->properties['d']->getConstraints();
+        self::assertTrue($dConstraint->allowNullAndEmptyString);
    }
 }

@@ -83,4 +87,7 @@ class ExpressionLanguageSyntaxDummy

    #[ExpressionLanguageSyntax(allowedVariables: ['foo', 'bar'], groups: ['my_group'])]
    private $c;
+
+    #[ExpressionLanguageSyntax(allowNullAndEmptyString: true)]
+    private $d;
 }
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/ExpressionLanguageSyntaxValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/ExpressionLanguageSyntaxValidatorTest.php
@@ -65,4 +65,46 @@ public function testExpressionIsNotValid()
            ->setCode(ExpressionLanguageSyntax::EXPRESSION_LANGUAGE_SYNTAX_ERROR)
            ->assertRaised();
    }
+
+    public function testNullIsValid()
+    {
+        $this->validator->validate(null, new ExpressionLanguageSyntax([
+            'allowNullAndEmptyString' => true,
+        ]));
+
+        $this->assertNoViolation();
+    }
+
+    /**
+     * @group legacy
+     */
+    public function testNullWithoutAllowOptionIsNotValid()
+    {
+        $this->expectExceptionMessage('Expected argument of type "string", "null" given');
+
+        $this->validator->validate(null, new ExpressionLanguageSyntax());
+    }
+
+    public function testEmptyStringIsValid()
+    {
+        $this->validator->validate('', new ExpressionLanguageSyntax([
+            'allowNullAndEmptyString' => true,
+        ]));
+
+        $this->assertNoViolation();
+    }
+
+    /**
+     * @group legacy
+     */
+    public function testEmptyStringWithoutAllowOptionIsNotValid()
+    {
+        $this->validator->validate('', new ExpressionLanguageSyntax());
+
+        $this->buildViolation('This value should be a valid expression.')
+            ->setParameter('{{ syntax_error }}', '"Unexpected token "end of expression" of value "" around position 1."')
+            ->setInvalidValue('')
+            ->setCode(ExpressionLanguageSyntax::EXPRESSION_LANGUAGE_SYNTAX_ERROR)
+            ->assertRaised();
+    }
 }
-Original file line number
+Diff line change
@@ -39,6 +39,10 @@ public function validate($expression, Constraint $constraint): void
                 throw new UnexpectedTypeException($constraint, ExpressionLanguageSyntax::class);
             }
+            if (true === $constraint->allowNullAndEmptyString && (null === $expression || '' === $expression)) {
+                return;
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            HeahDude
  

      

      

      


        Jun 28, 2021


      
    

  


        
      
  
  
  
    

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      The deprecation should be triggered here instead of the constraint constructor to ensure runtime context, otherwise it may be lost in the app cache warm up, something like:
if (null === $expression || '' === $expression) {
    if ($constraint->allowNullAndEmptyString) {
        return;
    }

    trigger_deprecation(...);
}
    
  
  


    

        
      
  
  
    
  
  
  
    
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            mpiot
  

      

      

      


        Jun 29, 2021


      
    

  


        
      
  
  
  
    

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      I'll wait for other comments about it, because all triggered deprecations in Constraints are in the Constraint class and not in the Validator (eg: Length, Range)
    
  
  


    

        
      
  
  
    
  
  
  
    
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            HeahDude
  

      

      

      


        Aug 27, 2021


      
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      I would say that it should never be the case, otherwise it may end up as symfony/symfony-docs#14785 (ref symfony/symfony-docs#14785 (comment)).
    
  
  


    

        
      
  
  
    
  
  
  
    
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+            }
             if (!\is_string($expression)) {
                 throw new UnexpectedValueException($expression, 'string');
             }
-          Expand Down