[Console] fix return type declarations

src/Symfony/Component/Console/Application.php

@@ -21,7 +21,6 @@ use Symfony\Component\Console\Event\ConsoleExceptionEvent;
 use Symfony\Component\Console\Event\ConsoleTerminateEvent;
 use Symfony\Component\Console\Exception\CommandNotFoundException;
 use Symfony\Component\Console\Exception\ExceptionInterface;
-use Symfony\Component\Console\Exception\LogicException;
 use Symfony\Component\Console\Formatter\OutputFormatter;
 use Symfony\Component\Console\Helper\DebugFormatterHelper;
 use Symfony\Component\Console\Helper\FormatterHelper;
@@ -457,13 +456,8 @@ class Application
             return null;
         }
 
-        if (null === $command->getDefinition()) {
-            throw new LogicException(sprintf('Command class "%s" is not correctly initialized. You probably forgot to call the parent constructor.', \get_class($command)));
-        }
-
-        if (!$command->getName()) {
-            throw new LogicException(sprintf('The command defined in "%s" cannot have an empty name.', \get_class($command)));
-        }
+        // Will throw if the command is not correctly initialized.
+        $command->getDefinition();
 
         $this->commands[$command->getName()] = $command;
 
@@ -1023,7 +1017,7 @@ class Application
     /**
      * Gets the name of the command based on input.
      *
-     * @return string The command name
+     * @return string|null
      */
     protected function getCommandName(InputInterface $input)
     {

src/Symfony/Component/Console/Command/Command.php

@@ -40,8 +40,8 @@ class Command
     private $aliases = [];
     private $definition;
     private $hidden = false;
-    private $help;
-    private $description;
+    private $help = '';
+    private $description = '';
     private $ignoreValidationErrors = false;
     private $applicationDefinitionMerged = false;
     private $applicationDefinitionMergedWithArgs = false;
@@ -105,7 +105,7 @@ class Command
     /**
      * Gets the helper set.
      *
-     * @return HelperSet A HelperSet instance
+     * @return HelperSet|null A HelperSet instance
      */
     public function getHelperSet()
     {
@@ -115,7 +115,7 @@ class Command
     /**
      * Gets the application instance for this command.
      *
-     * @return Application An Application instance
+     * @return Application|null An Application instance
      */
     public function getApplication()
     {
@@ -347,6 +347,10 @@ class Command
      */
     public function getDefinition()
     {
+        if (null === $this->definition) {
+            throw new LogicException(sprintf('Command class "%s" is not correctly initialized. You probably forgot to call the parent constructor.', \get_class($this)));
+        }
+
         return $this->definition;
     }
 
@@ -453,6 +457,10 @@ class Command
      */
     public function getName()
     {
+        if (!$this->name) {
+            throw new LogicException(sprintf('The command defined in "%s" cannot have an empty name.', \get_class($this)));
+        }
+
         return $this->name;
     }
 

src/Symfony/Component/Console/Question/Question.php

@@ -228,7 +228,7 @@ class Question
      *
      * The normalizer can ba a callable (a string), a closure or a class implementing __invoke.
      *
-     * @return callable
+     * @return callable|null
      */
     public function getNormalizer()
     {