callable parameter type as string

[spud]

The function map entry for PHP's set_exception_handler is

'set_exception_handler' => ['null|callable(Throwable):void', 'exception_handler'=>'null|callable(Throwable):void']

I have an exception handler function called dt_exception with the right function signature, so my code looks like:

set_exception_handler('dt_exception');

But PHPStan flags the code with

Parameter #1 $exception_handler of function set_exception_handler expects (callable(Throwable): void)|null, 'dt_exception' given.

The PHP docs for callables say "A PHP function is passed by its name as a string.," so I would expect any string to be valid, but bonus points for confirming that the string corresponds to a known function name. (There seems to be some debate as to whether or not "ClassName::staticMethod" should work as a string reference rather than array("ClassName","staticMethod"), but in my case I'm calling a raw function, not a static method).

How is PHPStan handling the validation of "callable" types? Is it correct to be flagging this?

[ondrejmirtes]

Can you reproduce the problem on phpstan.org?

[spud]

https://phpstan.org/r/6f0293f3-ebdf-4f86-8369-7f9146d691ce

That work?

[ondrejmirtes]

If I define those functions, there's no error: https://phpstan.org/r/0d27ab78-1272-4694-89e3-de20624820ee

[ondrejmirtes]

1. Does an error "Function not found" appear if you try to call dt_error() or dt_exception() normally?
2. Does following this guide work in fixing the error? https://phpstan.org/user-guide/discovering-symbols

[spud]

OK, getting deeper. I somehow managed to clear up the error with dt_exception (and I have no idea exactly what I did...I made so many changes/undo changes/removed a line that I can't reproduce the error anymore. I still get the dt_error flagged though.

So if I make changes to your function defintion to match mine -- adding the 2 optional parameters, I get only a note about them lacking a type hint:

https://phpstan.org/r/4ed05dc6-fc11-4c00-a5ff-c26f52cdd784

However, if I add my docblock for that function, I get the Parameter #1 $callback of function set_error_handler error again! So is there something wrong with my docblock?

https://phpstan.org/r/f3b537a1-f9f6-40e1-842c-c4204da935ce

[ondrejmirtes]

errline is supposed to be int: https://phpstan.org/r/62b22cf2-d835-40dc-9746-339aa0e5e711

[spud]

D'oh! Passing cleanly now. Cheers!