bug #118 [Sender] Assert recipient emails are always not empty strings (lchrusciel)

This PR was merged into the 1.7 branch.

Discussion
----------

| Q               | A
| --------------- | -----
| Bug fix?        | yes
| New feature?    | no
| BC breaks?      | no
| Deprecations?   | no
| Related tickets | 
| License         | MIT

In Sylius our "getEmail" contract on "Customer" is saying that email can be null. Of course, we should never pass null to the sender, however, the psalm is complaining that we've changed rules. with the #113. 

I'm in favour of enforcing this rule, but rather in runtime to keep all the builds green. We can change it with SyliusMailer 2.0

Related psalm test: https://psalm.dev/r/18ab1bda24

Commits
-------

7c8c2f7 [Sender] Assert recipient emails are always not empty strings

Author: Zales0123

src/Component/Sender/Sender.php

@@ -17,6 +17,7 @@
 use Sylius\Component\Mailer\Provider\EmailProviderInterface;
 use Sylius\Component\Mailer\Renderer\Adapter\AdapterInterface as RendererAdapterInterface;
 use Sylius\Component\Mailer\Sender\Adapter\AdapterInterface as SenderAdapterInterface;
+use Webmozart\Assert\Assert;
 
 final class Sender implements SenderInterface
 {
@@ -45,6 +46,8 @@ public function __construct(
      */
     public function send(string $code, array $recipients, array $data = [], array $attachments = [], array $replyTo = []): void
     {
+        Assert::allStringNotEmpty($recipients);
+
         $email = $this->provider->getEmail($code);
 
         if (!$email->isEnabled()) {

src/Component/Sender/SenderInterface.php

@@ -16,7 +16,7 @@
 interface SenderInterface
 {
     /**
-     * @param string[] $recipients A list of email addresses to receive the message.
+     * @param string[]|null[] $recipients A list of email addresses to receive the message. Providing null or empty string in the list of recipients is deprecated and will be removed in SyliusMailerBundle 2.0
      * @param string[] $attachments A list of file paths to attach to the message.
      * @param string[] $replyTo A list of email addresses to set as the Reply-To address for the message.
      */

src/Component/spec/Sender/SenderSpec.php

@@ -14,6 +14,7 @@
 namespace spec\Sylius\Component\Mailer\Sender;
 
 use PhpSpec\ObjectBehavior;
+use Prophecy\Argument;
 use Sylius\Component\Mailer\Model\EmailInterface;
 use Sylius\Component\Mailer\Provider\DefaultSettingsProviderInterface;
 use Sylius\Component\Mailer\Provider\EmailProviderInterface;
@@ -66,4 +67,27 @@ function it_does_not_send_disabled_emails(
 
         $this->send('bar', ['john@example.com'], ['foo' => 2], []);
     }
+
+    function it_throws_an_exception_if_wrong_value_is_provided_as_recipient_email(
+        RendererAdapterInterface $rendererAdapter,
+        SenderAdapterInterface $senderAdapter
+    ): void {
+        $rendererAdapter->render(Argument::any())->shouldNotBeCalled();
+        $senderAdapter->send(Argument::any())->shouldNotBeCalled();
+
+        $this->shouldThrow(\InvalidArgumentException::class)->during(
+            'send',
+            ['bar', ['john@example.com', null], ['foo' => 2], []],
+        );
+
+        $this->shouldThrow(\InvalidArgumentException::class)->during(
+            'send',
+            ['bar', [5], ['foo' => 2], []],
+        );
+
+        $this->shouldThrow(\InvalidArgumentException::class)->during(
+            'send',
+            ['bar', [''], ['foo' => 2], []],
+        );
+    }
 }