Fix tests + iterator_to_array() must implement interface Traversable

Author: symfonyaml

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

@@ -52,8 +52,8 @@ public function validate($value, Constraint $constraint)
                 throw new ConstraintDefinitionException('The Choice constraint expects a valid callback.');
             }
             $choices = $choices();
-            if (is_iterable($choices)) {
-                $choices = iterator_to_array($choices, true);
+            if ($choices instanceof \Traversable) {
+                $choices = iterator_to_array($choices);
             }
             if (!\is_array($choices)) {
                 throw new ConstraintDefinitionException(\sprintf('The Choice constraint expects the callback to return an iterable value, got "%s".', get_debug_type($choices)));

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

@@ -200,7 +200,7 @@ public function testInvalidChoice(Choice $constraint)
     public function testInvalidChoiceCallbackContextMethod()
     {
         $this->expectException(ConstraintDefinitionException::class);
-        $this->expectExceptionMessage('The Choice constraint expects the callback to return an iterable value, got null.');
+        $this->expectExceptionMessage('The Choice constraint expects the callback to return an iterable value, got "null".');
         // search $this for "staticCallbackInvalid"
         $this->setObject($this);