[Validator] Fix NotBlank validator to treat whitespace-only strings as blank

Constraints/NotBlankValidator.php

@@ -18,6 +18,7 @@
 /**
  * @author Bernhard Schussek <[email protected]>
  * @author Kévin Dunglas <[email protected]>
+ * @author Lionel Kimb's <[email protected]>
  */
 class NotBlankValidator extends ConstraintValidator
 {
@@ -35,6 +36,8 @@ public function validate(mixed $value, Constraint $constraint): void
             $value = ($constraint->normalizer)($value);
         }
 
+        $value = is_string($value) ? trim($value) : $value;
+
         if (false === $value || (empty($value) && '0' != $value)) {
             $this->context->buildViolation($constraint->message)
                 ->setParameter('{{ value }}', $this->formatValue($value))

Tests/Constraints/NotBlankValidatorTest.php

@@ -71,6 +71,20 @@ public function testBlankIsInvalid()
             ->assertRaised();
     }
 
+    public function testBlankTextIsInvalid()
+    {
+        $constraint = new NotBlank([
+            'message' => 'myMessage',
+        ]);
+
+        $this->validator->validate('              ', $constraint);
+
+        $this->buildViolation('myMessage')
+            ->setParameter('{{ value }}', '""')
+            ->setCode(NotBlank::IS_BLANK_ERROR)
+            ->assertRaised();
+    }
+
     public function testFalseIsInvalid()
     {
         $constraint = new NotBlank([