Custom driver and ExceptionConverter

[gitomato]

Feature Request

Q	A
New Feature	no
RFC	no

Summary

When writing a custom driver, at some point we need to implement ExceptionConverter interface.

The convert() method requires to return a DriverException.
However this class is marked as internal and triggers a warning:

The "Doctrine\DBAL\Exception\DriverException::__construct()" method is considered internal. It may change without further notice. You should not extend it from "App\DBAL\Exception\DriverException".

Could you consider returning the Doctrine\DBAL\Driver\Exception interface instead in the future?

PS: thanks for you amazing work!

[derrabus]

The convert() method requires to return a DriverException. However this class is marked as internal and triggers a warning:

The "Doctrine\DBAL\Exception\DriverException::__construct()" method is considered internal. It may change without further notice. You should not extend it from "App\DBAL\Exception\DriverException".

We should probably not flag the constructor as @internal. I'm open to removing this annotation on 4.1.x because custom drivers need to call that constructor. Please send a PR.

That being said: this might not be the only "internal" API you will need to call for your custom driver. Please keep opening issues if you run into more of them. ✌🏻

Could you consider returning the Doctrine\DBAL\Driver\Exception interface instead in the future?

That's a terrible idea. The whole point of the exception converter is to upcast an exception specific to your database to one of the well-known exceptions that extend DriverException. If the converter returned anything else, the wrapper layer or the application wouldn't know what to do with that exception.