[Validator] [Choice] Fix callback option if not array returned

Author: symfonyaml

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

@@ -55,6 +55,9 @@ public function validate($value, Constraint $constraint)
                 throw new ConstraintDefinitionException('The Choice constraint expects a valid callback.');
             }
             $choices = $choices();
+            if (!is_array($choices)) {
+                throw new ConstraintDefinitionException(sprintf('The Choice constraint callback "%s" is expected to return an array, but returned "%s".', trim($this->formatValue($constraint->callback), '"'), get_debug_type($choices)));
+            }
         } else {
             $choices = $constraint->choices;
         }

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

@@ -39,6 +39,11 @@ public function objectMethodCallback()
         return ['foo', 'bar'];
     }
 
+    public static function staticCallbackInvalid()
+    {
+        return null;
+    }
+
     public function testExpectArrayIfMultipleIsTrue()
     {
         $this->expectException(UnexpectedValueException::class);
@@ -134,6 +139,19 @@ public function testValidChoiceCallbackContextMethod()
         $this->assertNoViolation();
     }
 
+    public function testInvalidChoiceCallbackContextMethod()
+    {
+        $this->expectException(ConstraintDefinitionException::class);
+        $this->expectExceptionMessage('The Choice constraint callback "staticCallbackInvalid" is expected to return an array, but returned "null".');
+
+        // search $this for "staticCallbackInvalid"
+        $this->setObject($this);
+
+        $constraint = new Choice(['callback' => 'staticCallbackInvalid']);
+
+        $this->validator->validate('bar', $constraint);
+    }
+
     public function testValidChoiceCallbackContextObjectMethod()
     {
         // search $this for "objectMethodCallback"