[Scheduler] have TriggerInterface extend \Stringable

src/Symfony/Component/Scheduler/Tests/Generator/MessageGeneratorTest.php

@@ -135,6 +135,11 @@ public static function messagesProvider(): \Generator
             ],
             'schedule' => [
                 RecurringMessage::trigger(new class() implements TriggerInterface {
+                    public function __toString(): string
+                    {
+                        return 'foo';
+                    }
+
                     public function getNextRunDate(\DateTimeImmutable $run): ?\DateTimeImmutable
                     {
                         return null;

src/Symfony/Component/Scheduler/Trigger/CallbackTrigger.php

@@ -25,6 +25,11 @@ public function __construct(callable $callback)
         $this->callback = $callback(...);
     }
 
+    public function __toString(): string
+    {
+        return spl_object_hash($this->callback);
+    }
+
     public function getNextRunDate(\DateTimeImmutable $run): ?\DateTimeImmutable
     {
         return ($this->callback)($run);

src/Symfony/Component/Scheduler/Trigger/CronExpressionTrigger.php

@@ -21,7 +21,7 @@
  *
  * @experimental
  */
-final class CronExpressionTrigger implements TriggerInterface, \Stringable
+final class CronExpressionTrigger implements TriggerInterface
 {
     public function __construct(
         private readonly CronExpression $expression = new CronExpression('* * * * *'),

src/Symfony/Component/Scheduler/Trigger/DatePeriodTrigger.php

@@ -21,6 +21,16 @@ public function __construct(
     ) {
     }
 
+    public function __toString(): string
+    {
+        return sprintf(
+            '%s - %s, %s',
+            $this->period->getStartDate()->format(\DateTimeInterface::ATOM),
+            $this->period->getEndDate()?->format(\DateTimeInterface::ATOM) ?? '(inf)',
+            '-',
+        );
+    }
+
     public function getNextRunDate(\DateTimeImmutable $run): ?\DateTimeImmutable
     {
         $iterator = $this->period->getIterator();

src/Symfony/Component/Scheduler/Trigger/ExcludeTimeTrigger.php

@@ -23,6 +23,11 @@ public function __construct(
     ) {
     }
 
+    public function __toString(): string
+    {
+        return sprintf('%s, from: %s, until: %s', $this->inner, $this->from->format(\DateTimeInterface::ATOM), $this->until->format(\DateTimeInterface::ATOM));
+    }
+
     public function getNextRunDate(\DateTimeImmutable $run): ?\DateTimeImmutable
     {
         $nextRun = $this->inner->getNextRunDate($run);

src/Symfony/Component/Scheduler/Trigger/TriggerInterface.php

@@ -14,7 +14,7 @@
 /**
  * @experimental
  */
-interface TriggerInterface
+interface TriggerInterface extends \Stringable
 {
     public function getNextRunDate(\DateTimeImmutable $run): ?\DateTimeImmutable;
 }