[Console] Fix inconsistent result for choice questions in non-interactive mode

Author: Robin Chalas

Helper/QuestionHelper.php

@@ -49,7 +49,13 @@ public function ask(InputInterface $input, OutputInterface $output, Question $qu
         if (!$input->isInteractive()) {
             $default = $question->getDefault();
 
-            if (null !== $default && $question instanceof ChoiceQuestion) {
+            if (null === $default) {
+                return $default;
+            }
+
+            if ($validator = $question->getValidator()) {
+                return \call_user_func($question->getValidator(), $default);
+            } elseif ($question instanceof ChoiceQuestion) {
                 $choices = $question->getChoices();
 
                 if (!$question->isMultiselect()) {

Tests/Helper/QuestionHelperTest.php

@@ -137,6 +137,9 @@ public function testAskChoiceNonInteractive()
         $question->setMultiselect(true);
         $this->assertNull($questionHelper->ask($this->createStreamableInputInterfaceMock($inputStream, false), $this->createOutputInterface(), $question));
 
+        $question = new ChoiceQuestion('Who are your favorite superheros?', ['a' => 'Batman', 'b' => 'Superman'], 'a');
+        $this->assertSame('a', $questionHelper->ask($this->createStreamableInputInterfaceMock('', false), $this->createOutputInterface(), $question), 'ChoiceQuestion validator returns the key if it\'s a string');
+
         try {
             $question = new ChoiceQuestion('Who are your favorite superheros?', $heroes, '');
             $question->setMultiselect(true);