Fix #922, ProxyGenerator missing assert

[GameplayJDK]

Upon suggestion I've copied this description from the Ticket.

Hello everyone,

while working on #917 I noticed a missing assert() in the method getParameterType() of the ProxyGenerator.

The ReflectionParameter::getDeclaringFunction() method returns a ReflectionFunctionAbstract, the type hint of ProxyGenerator::formatType(...) is ReflectionMethod, one of two possible implementations, the other is ReflectionFunction.

    /**
     * @return string|null
     */
    private function getParameterType(ReflectionParameter $parameter)
    {
        if (! $parameter->hasType()) {
            return null;
        }

        return $this->formatType($parameter->getType(), $parameter->getDeclaringFunction(), $parameter);
    }

I'd propose a change from the above code to the code below:

    /**
     * @return string|null
     */
    private function getParameterType(ReflectionParameter $parameter)
    {
        if (! $parameter->hasType()) {
            return null;
        }

        $declaringFunction = $parameter->getDeclaringFunction();

        assert($declaringFunction instanceof ReflectionMethod);

        return $this->formatType($parameter->getType(), $declaringFunction, $parameter);
    }

3v4l.org snippet

Of course the assertion will always be true, but this theoretical type mismatch was pointed out by my IDE, which confused me at first. In my opinion this would make the code more clean and prevent any future confusion about what type is expected.

[greg0ire]

Please amend your commit message according to the contributing guide, currently it's hard to guess why the assert is missing solely based on that message.

[malarzm]

@greg0ire are you ok with current commit message?

[greg0ire]

Yes, it looks great!

[greg0ire]

Thanks @GameplayJDK !