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Date: Mon, 11 Aug 2014 11:30:47 +0100
Message-ID: <CAGAGxba9=rwSjSOhfQZbuKwOzUYXMMTbse0csRihtp=yZFpHWg@mail.gmail.com>
To: Tom Oram <tom@scl.co.uk>
Cc: PHP Internals <internals@lists.php.net>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [PHP-DEV] Reflection to remove final
From: daverandom@php.net (Chris Wright)

Hi Tom

On 9 August 2014 11:35, Tom Oram <tom@scl.co.uk> wrote:
> I've just been looking back at the history of this previous conversation...
>
> http://marc.info/?l=php-internals&m=132673741606531&w=2
>
> as a mockist tester I'd really REALLY like to see this be possible but I
> can see the problem with the original patch modifying the actual existing
> class.
>
> One solution I propose is rather than modify it would it be possible for
> the reflection class to be able to duplicate the class with the finals
> removed so something like this could be possible:
>
> final class A
> {
> }
>
> $r = new ReflectionClass('A');
>
> $r->defineExtendableClass('ExtendableA');
>
> class MockA extends ExtendabledA
> {
> }
>
> I'm unfamiliar with the PHP codebase so I thought I'd just ask here to find
> out if it sounds possible before diving into the code

Yes it's definitely possible, all you need to do is duplicate the
class definition and perform &= ~ZEND_ACC_FINAL on the class entry
structure flags, however...

Joe Watkins' uopz [1][2] extension already provides a mechanism to do
what you want to do. I've not tested this, but I quickly bounced a
couple of questions off Joe and I believe this should work:

final class A {}
class MockA {}
uopz_extend('MockA', 'A');

A word of warning though: if a *method* is explicitly declared final
(rather than implicitly because the class is final), and the mock
overrides this method, this will be checked at runtime and cause a
fatal error. In order to work around this, you need to use
uopz_flags() as well:

class B {
   final public function c() {}
}
class MockB {
    public function c() {}
}
uopz_flags('B', 'c', ZEND_ACC_PUBLIC); // remove ZEND_ACC_FINAL
uopz_flags('B', 'c', );

Note also that if you are using this approach - modifying symbol flags
at runtime - it is important that you do not declare the inheritance
relationship explicitly (i.e. class MockA extends A {}) as this will
error out before the runtime modifications are made.

If you want to look at adding similar functionality to reflection,
then looking at how uopz works would be a good place to start - but
personally I'm not sure if there's any value in this since anyone who
wants the functionality can just use uopz.

[1] https://github.com/krakjoe/uopz
[2] http://php.net/uopz

> Thoughts?
>
> Regards,
> Tom

Thanks, Chris