Fix rendering shortcodes in subject

[MAILPOET-3333]

lib/Cron/Workers/SendingQueue/Tasks/Shortcodes.php

@@ -32,18 +32,24 @@ class Shortcodes {
     }
     if ($queue instanceof SendingQueueEntity) {
       $shortcodes->setQueue($queue);
+    } else {
+      $shortcodes->setQueue(null);
     }
     if ($newsletter instanceof \MailPoet\Models\Newsletter && $newsletter->id) {
       $newsletter = $newsletterRepository->findOneById($newsletter->id);
     }
     if ($newsletter instanceof NewsletterEntity) {
       $shortcodes->setNewsletter($newsletter);
+    } else {
+      $shortcodes->setNewsletter(null);
     }
     if ($subscriber instanceof Subscriber && $subscriber->id) {
       $subscriber = $subscribersRepository->findOneById($subscriber->id);
     }
     if ($subscriber instanceof SubscriberEntity) {
       $shortcodes->setSubscriber($subscriber);
+    } else {
+      $shortcodes->setSubscriber(null);
     }
     return $shortcodes->replace($content, $contentSource);
   }

lib/Newsletter/Shortcodes/Categories/Subscriber.php

@@ -34,18 +34,21 @@ class Subscriber implements CategoryInterface {
     string $content = '',
     bool $wpUserPreview = false
   ): ?string {
+    if (!($subscriber instanceof SubscriberEntity)) {
+      return $shortcodeDetails['shortcode'];
+    }
     $defaultValue = ($shortcodeDetails['action_argument'] === 'default') ?
       $shortcodeDetails['action_argument_value'] :
       '';
     switch ($shortcodeDetails['action']) {
       case 'firstname':
-        return (($subscriber instanceof SubscriberEntity) && !empty($subscriber->getFirstName())) ? $subscriber->getFirstName() : $defaultValue;
+        return (!empty($subscriber->getFirstName())) ? $subscriber->getFirstName() : $defaultValue;
       case 'lastname':
-        return (($subscriber instanceof SubscriberEntity) && !empty($subscriber->getLastName())) ? $subscriber->getLastName() : $defaultValue;
+        return !empty($subscriber->getLastName()) ? $subscriber->getLastName() : $defaultValue;
       case 'email':
-        return ($subscriber instanceof SubscriberEntity) ? $subscriber->getEmail() : $defaultValue;
+        return $subscriber->getEmail();
       case 'displayname':
-        if (($subscriber instanceof SubscriberEntity) && $subscriber->getWpUserId()) {
+        if ($subscriber->getWpUserId()) {
           $wpUser = WPFunctions::get()->getUserdata($subscriber->getWpUserId());
           return $wpUser->user_login; // phpcs:ignore Squiz.NamingConventions.ValidVariableName.NotCamelCaps
         }

lib/Newsletter/Shortcodes/Shortcodes.php

@@ -49,7 +49,7 @@ class Shortcodes {
     $this->subscriberCategory = $subscriberCategory;
   }
 
-  public function setNewsletter(NewsletterEntity $newsletter): void {
+  public function setNewsletter(NewsletterEntity $newsletter = null): void {
     $this->newsletter = $newsletter;
   }
 
@@ -57,7 +57,7 @@ class Shortcodes {
     $this->subscriber = $subscriber;
   }
 
-  public function setQueue(SendingQueueEntity $queue): void {
+  public function setQueue(SendingQueueEntity $queue = null): void {
     $this->queue = $queue;
   }
 

tests/integration/Newsletter/ShortcodesTest.php

@@ -160,14 +160,19 @@ class ShortcodesTest extends \MailPoetTest {
   }
 
   public function testSubscriberShortcodesRequireSubscriberObjectOrFalseValue() {
-    // when subscriber is empty, default value is returned
+    // when subscriber is empty, original value is returned
     $this->shortcodesObject->setSubscriber(null);
     $result = $this->shortcodesObject->process(['[subscriber:firstname | default:test]']);
-    expect($result[0])->equals('test');
+    expect($result[0])->equals('[subscriber:firstname | default:test]');
     // when subscriber is an object, proper value is returned
     $this->shortcodesObject->setSubscriber($this->subscriber);
     $result = $this->shortcodesObject->process(['[subscriber:firstname | default:test]']);
     expect($result[0])->equals($this->subscriber->getFirstName());
+    // when subscriber hasn't name, the default value is returned
+    $this->subscriber->setFirstName('');
+    $this->shortcodesObject->setSubscriber($this->subscriber);
+    $result = $this->shortcodesObject->process(['[subscriber:firstname | default:test]']);
+    expect($result[0])->equals('test');
   }
 
   public function testSubscriberFirstAndLastNameShortcodesReturnDefaultValueWhenDataIsEmpty() {