You have injected the EntityManager via parameter $em. This is generally not recommended as it might get closed and become unusable. Instead, it is recommended to inject the ManagerRegistry and retrieve the EntityManager via getManager() each time you need it.
The EntityManager might become unusable for example if a transaction is
rolled back and it gets closed. Let’s assume that somewhere in your application,
or in a third-party library, there is code such as the following:
functionsomeFunction(ManagerRegistry$registry){$em=$registry->getManager();$em->getConnection()->beginTransaction();try{// Do something.$em->getConnection()->commit();}catch(\Exception$ex){$em->getConnection()->rollback();$em->close();throw$ex;}}
If that code throws an exception and the EntityManager is closed. Any other
code which depends on the same instance of the EntityManager during this
request will fail.
On the other hand, if you instead inject the ManagerRegistry, the getManager()
method guarantees that you will always get a usable manager instance.
This check looks for PHPDoc comments describing methods or function parameters that do not exist on the corresponding method or function.
Consider the following example. The parameter
$italyis not defined by the methodfinale(...).The most likely cause is that the parameter was removed, but the annotation was not.