JobSchedule: clones cron expression

CHANGELOG.md

@@ -44,6 +44,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - `ManagedScheduler`
 	- acquired job locks are scoped just to their id - changing run frequency or job name will not make process loose
 	  the lock
+- `CronExpression` is cloned after being added to job manager or scheduler for job immutability
 
 ### Removed
 

src/Job/JobSchedule.php

@@ -30,7 +30,7 @@ public static function create(
 		$self = new self();
 		$self->jobConstructor = null;
 		$self->job = $job;
-		$self->expression = $expression;
+		$self->expression = clone $expression;
 		$self->repeatAfterSeconds = $repeatAfterSeconds;
 
 		return $self;
@@ -48,7 +48,7 @@ public static function createLazy(
 	{
 		$self = new self();
 		$self->jobConstructor = $jobConstructor;
-		$self->expression = $expression;
+		$self->expression = clone $expression;
 		$self->repeatAfterSeconds = $repeatAfterSeconds;
 
 		return $self;

tests/Unit/Job/JobScheduleTest.php

@@ -20,7 +20,8 @@ public function test(): void
 		$schedule = JobSchedule::create($job, $expression, $seconds);
 
 		self::assertSame($job, $schedule->getJob());
-		self::assertSame($expression, $schedule->getExpression());
+		self::assertEquals($expression, $schedule->getExpression());
+		self::assertNotSame($expression, $schedule->getExpression());
 		self::assertSame($seconds, $schedule->getRepeatAfterSeconds());
 	}
 
@@ -35,7 +36,8 @@ public function testLazy(): void
 
 		self::assertInstanceOf(CallbackJob::class, $schedule->getJob());
 		self::assertSame($schedule->getJob(), $schedule->getJob());
-		self::assertSame($expression, $schedule->getExpression());
+		self::assertEquals($expression, $schedule->getExpression());
+		self::assertNotSame($expression, $schedule->getExpression());
 		self::assertSame($seconds, $schedule->getRepeatAfterSeconds());
 	}