Method Zend\Code\Generator\ValueGenerator::__toString() must not throw an exception (with PHP 7.3)

[k00ni]

The class ValueGenerator may throw an exception inside __toString which is forbidden (look for Exceptions can not be thrown from __toString() methods.) and leads to a fatal error in my case. I am running a Symfony application, which indirectly uses zend-code.

Are you aware of this? I would propose moving the functionality in a separate function or not throw an exception in __toString (or referenced functions) at all.

Thank you for the feedback.

[michalbundyra]

@k00ni Since PHP 7.4 we can throw exceptions in __toString() method - see:
https://www.php.net/manual/en/migration74.new-features.php#migration74.new-features.core.tostring-exceptions

Can you provide more details about your use case when you are getting the exception? Thanks!

[k00ni]

Hi @michalbundyra, thank you for the quick reply.

Since PHP 7.4 we can throw exceptions in __toString() method

Ok, good to know :)

Can you provide more details about your use case when you are getting the exception?

I am running PHP 7.3, no xdebug.

My use case involves:

• Symfony 4.4.1
• Doctrine ORM 2.6.6
• PHPUnit 8.x

When running a simple test which requires the Kernel and Doctrine, i get the following error:

Fatal error: Method Zend\Code\Generator\ValueGenerator::__toString() must not throw an 
exception, caught ErrorException: Warning: get_class() expects parameter 1 to be object, 
resource given in 
/var/www/html/vendor/zendframework/zend-code/src/Generator/ParameterGenerator.php on line 0
!!  PHP Fatal error:  Method Zend\Code\Generator\ValueGenerator::__toString() must not 
throw an exception, caught ErrorException: Warning: get_class() expects parameter 1 to 
be object, resource given in 
/var/www/html/vendor/zendframework/zend-code/src/Generator/ParameterGenerator.php on line 0
!!  Symfony\Component\ErrorHandler\Error\FatalError {#1977
!!    -error: array:4 [
!!      "type" => 1
!!      "message" => "Method Zend\Code\Generator\ValueGenerator::__toString() must not
throw an exception, caught ErrorException: Warning: get_class() expects parameter 1 to be 
object, resource given"
!!      "file" => "/var/www/html/vendor/zendframework/zend-code/src/Generator/ParameterGenerator.php"
!!      "line" => 0
!!    ]
!!    #message: "Error: Method Zend\Code\Generator\ValueGenerator::__toString() must 
not throw an exception, caught ErrorException: Warning: get_class() expects parameter 
1 to be object, resource given"
!!    #code: 0
!!    #file: "./vendor/zendframework/zend-code/src/Generator/ParameterGenerator.php"
!!    #line: 0
!!  }

I am not familiar with Symfony, Doctrine or Zend internals, therefore can't located the source of the error. I am not even sure, if that is "your" problem, but i thought its a good start to ask the first one in the line.

---

EDIT: It must be related to symfony/proxy-manager-bridge, without it installed, i am not getting the error.

[k00ni]

I moved on to another solution for my problem, which means, i don't get this error anymore. But it maybe still of interest to you. Please close, if not.

[michalbundyra]

@k00ni I see the issue - in case value is resource in the exception message we try to get_class of resource, which is not working:

zend-code/src/Generator/ValueGenerator.php

Lines 438 to 442 in a277be9

	case self::TYPE_OTHER:
	default:
	throw new Exception\RuntimeException(
	sprintf('Type "%s" is unknown or cannot be used as property default value.', get_class($value))
	);

Still, seems to be that your code in some place is (was?) invalid.

Would you be able to share your solution which solve your problem, please?

[k00ni]

I had problems getting PHPUnit 8.x + Doctrine 2.7 running with Symfony 4.4.1. There was no PHP code involved, only YAML configuration.

After hours of searching it resulted in the following solution: symfony/symfony-docs#12788 (comment) .

I got the error above when trying to setup Doctrine to use entity manager in PHPUnit integration tests. Unfortunately, i can't find my configuration at that time anymore. I am still new to this and its hard to track all these changes and new features/components.

[k00ni]

Thank you for the refinements.