Interfaces and ReflectionMethod::isConstructor()

Am 28.03.2020 um 08:44 schrieb Sebastian Bergmann:

<?php
interface I
{
public function __construct();
}

var_dump((new ReflectionMethod(I::class, '__construct'))->isConstructor());

Here is the version of the script for testing with dead versions of PHP:
https://3v4l.org/fMCub

I recently received a bug report for PHPUnit [1] that with PHP 8 test
doubles (test stubs or mock objects) can no longer be created for
interfaces that declare a constructor.

I was able to reproduce this [2] and learned that PHPUnit's
canMockMethod() [3] returns a different result on PHP 8 compared to PHP

7. This is due to the return value of ReflectionMethod::isConstructor()
   when the ReflectionMethod object was created for an interface.

Here is a minimal, self-contained, reproducing test case:

<?php
interface I
{
public function __construct();
}

var_dump((new ReflectionMethod(I::class, '__construct'))->isConstructor());

The code shown above yields the following result:

• bool(true) for PHP 5.0.0 and PHP 5.0.1
• bool(false) for PHP 5.0.2 through PHP 7.4.4
• bool(true) for PHP 8.0-dev

I think that the behaviour in PHP 8 (and PHP 5.0.0 and PHP 5.0.1) is
correct. But I also think that constructor declarations have no place in
interfaces ... so I am confused. Which is why I did not open a ticket on
bugs.php.net and bring this topic to this list instead.

To the best of my knowledge, this change in behaviour of isConstructor()
between PHP 7 and PHP 8 is not yet documented. If it is intentional and
here to stay then it should be documented.

I can deal with this in PHPUnit's code either way, but need to know what
the plan here is.

The relevant change[1] is that now the class entry members
serialize_func, unserialize_func, constructor, destructor and clone are
set, if the respective methods are declared on an interface.

[1]
https://github.com/php/php-src/pull/3846/files#diff-3a8139128d4026ce0cb0c86beba4e6b9L5549-R5605

--
Christoph M. Becker

Am 28.03.2020 um 08:44 schrieb Sebastian Bergmann:

I can deal with this in PHPUnit's code either way, but need to know what
the plan here is.

I worked around the issue now [1].

--
[1]
https://github.com/sebastianbergmann/phpunit/commit/477798f6b226e830d358bc102cd02bb2e52cfdb2