minor #27203 [Messenger][DX] Uses a default receiver when only one is defined (sroze)

This PR was squashed before being merged into the 4.1 branch (closes #27203).

Discussion
----------

[Messenger][DX] Uses a default receiver when only one is defined

| Q             | A
| ------------- | ---
| Branch?       | 4.1
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | ø
| License       | MIT
| Doc PR        | ø

When using only one receiver, as a developer, it makes no sense for me to have to precise the receiver name when using the `messenger:consume-messages` command. This is the change:

```patch
- bin/console messenger:consume-messages default
+ bin/console messenger:consume-messages
```

If I have more than one transport configured, I'll get the following message:

>
>  You have 0 or more than one receiver (no default have been found). You need to specify the receiver name with an argument.
>

Commits
-------

8315b868d5 [Messenger][DX] Uses a default receiver when only one is defined

Author: sroze

Command/ConsumeMessagesCommand.php

@@ -37,14 +37,16 @@ class ConsumeMessagesCommand extends Command
     private $bus;
     private $receiverLocator;
     private $logger;
+    private $defaultReceiverName;
 
-    public function __construct(MessageBusInterface $bus, ContainerInterface $receiverLocator, LoggerInterface $logger = null)
+    public function __construct(MessageBusInterface $bus, ContainerInterface $receiverLocator, LoggerInterface $logger = null, string $defaultReceiverName = null)
     {
         parent::__construct();
 
         $this->bus = $bus;
         $this->receiverLocator = $receiverLocator;
         $this->logger = $logger;
+        $this->defaultReceiverName = $defaultReceiverName;
     }
 
     /**
@@ -54,7 +56,7 @@ protected function configure(): void
     {
         $this
             ->setDefinition(array(
-                new InputArgument('receiver', InputArgument::REQUIRED, 'Name of the receiver'),
+                new InputArgument('receiver', $this->defaultReceiverName ? InputArgument::OPTIONAL : InputArgument::REQUIRED, 'Name of the receiver', $this->defaultReceiverName),
                 new InputOption('limit', 'l', InputOption::VALUE_REQUIRED, 'Limit the number of received messages'),
                 new InputOption('memory-limit', 'm', InputOption::VALUE_REQUIRED, 'The memory limit the worker can consume'),
                 new InputOption('time-limit', 't', InputOption::VALUE_REQUIRED, 'The time limit in seconds the worker can run'),

DependencyInjection/MessengerPass.php

@@ -164,26 +164,32 @@ private function guessHandledClasses(\ReflectionClass $handlerClass, string $ser
     private function registerReceivers(ContainerBuilder $container)
     {
         $receiverMapping = array();
-        foreach ($container->findTaggedServiceIds($this->receiverTag) as $id => $tags) {
-            foreach ($tags as $tag) {
-                $receiverMapping[$id] = new Reference($id);
+        $taggedReceivers = $container->findTaggedServiceIds($this->receiverTag);
+
+        foreach ($taggedReceivers as $id => $tags) {
+            $receiverMapping[$id] = new Reference($id);
 
+            foreach ($tags as $tag) {
                 if (isset($tag['name'])) {
                     $receiverMapping[$tag['name']] = $receiverMapping[$id];
                 }
             }
         }
 
+        if (1 === \count($taggedReceivers) && $container->hasDefinition('console.command.messenger_consume_messages')) {
+            $container->getDefinition('console.command.messenger_consume_messages')->replaceArgument(3, (string) current($receiverMapping));
+        }
+
         $container->getDefinition('messenger.receiver_locator')->replaceArgument(0, $receiverMapping);
     }
 
     private function registerSenders(ContainerBuilder $container)
     {
         $senderLocatorMapping = array();
         foreach ($container->findTaggedServiceIds($this->senderTag) as $id => $tags) {
-            foreach ($tags as $tag) {
-                $senderLocatorMapping[$id] = new Reference($id);
+            $senderLocatorMapping[$id] = new Reference($id);
 
+            foreach ($tags as $tag) {
                 if (isset($tag['name'])) {
                     $senderLocatorMapping[$tag['name']] = $senderLocatorMapping[$id];
                 }

Tests/DependencyInjection/MessengerPassTest.php

@@ -16,6 +16,7 @@
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\ServiceLocator;
+use Symfony\Component\Messenger\Command\ConsumeMessagesCommand;
 use Symfony\Component\Messenger\Transport\AmqpExt\AmqpReceiver;
 use Symfony\Component\Messenger\Transport\AmqpExt\AmqpSender;
 use Symfony\Component\Messenger\Handler\Locator\ContainerHandlerLocator;
@@ -116,6 +117,41 @@ public function testItRegistersReceiversWithoutTagName()
         $this->assertEquals(array(AmqpReceiver::class => new Reference(AmqpReceiver::class)), $container->getDefinition('messenger.receiver_locator')->getArgument(0));
     }
 
+    public function testItRegistersOneReceiverAndSetsTheDefaultOneOnTheCommand()
+    {
+        $container = $this->getContainerBuilder();
+        $container->register('console.command.messenger_consume_messages', ConsumeMessagesCommand::class)->setArguments(array(
+            new Reference('message_bus'),
+            new Reference('messenger.receiver_locator'),
+            null,
+            null,
+        ));
+
+        $container->register(AmqpReceiver::class, AmqpReceiver::class)->addTag('messenger.receiver', array('name' => 'amqp'));
+
+        (new MessengerPass())->process($container);
+
+        $this->assertSame(AmqpReceiver::class, $container->getDefinition('console.command.messenger_consume_messages')->getArgument(3));
+    }
+
+    public function testItRegistersMultipleReceiversAndDoesNotSetTheDefaultOneOnTheCommand()
+    {
+        $container = $this->getContainerBuilder();
+        $container->register('console.command.messenger_consume_messages', ConsumeMessagesCommand::class)->setArguments(array(
+            new Reference('message_bus'),
+            new Reference('messenger.receiver_locator'),
+            null,
+            null,
+        ));
+
+        $container->register(AmqpReceiver::class, AmqpReceiver::class)->addTag('messenger.receiver', array('name' => 'amqp'));
+        $container->register(DummyReceiver::class, DummyReceiver::class)->addTag('messenger.receiver', array('name' => 'dummy'));
+
+        (new MessengerPass())->process($container);
+
+        $this->assertNull($container->getDefinition('console.command.messenger_consume_messages')->getArgument(3));
+    }
+
     public function testItRegistersSenders()
     {
         $container = $this->getContainerBuilder();