On 18-3-2022 14:37, Christoph M. Becker wrote:
On 16.03.2022 at 06:52, Juliette Reinders Folmer wrote:
I've just been looking in detail at the Partially Supported Callables
deprecation RFC:
https://wiki.php.net/rfc/deprecate_partially_supported_callables
The RFC explicitly excludes the `is_callable()` function and the
`callable` type from throwing deprecation notices.
The |is_callable()| function and |callable| type remain side-effect
free and do not throw a deprecation warning. They will continue to
accept these callables until support is removed entirely.
While I can fully support this for the `callable` type, I wonder if the
decision to not throw a deprecation on use in `is_callable()` is the
right one (though I understand the desire to keep it side-effect free).
Consider these code samples:
function foo(callable $callback) {}
foo('static::method');
This function call not throwing a deprecation is not problematic as in
PHP 9.0 the function will start throwing a TypeError.
if (is_callable('static::method')) {
static::method();
}
The second code sample, however, is problematic, as in PHP 9.0, the
behaviour of this code will be silently reversed for those callbacks
which would previously result in `is_callable()` returning true, which
makes this a potentially dangerous change without deprecation notice.
Would anyone care to enlighten me as to whether this was given due
consideration ?
Frankly, I don't know. Apparently, there was almost no discussion about
that RFC. Part of the reasoning to not raise E_DEPRECATED when calling
is_callable() was likely the typical use case
$callable = …;
if (is_callable($callable)) {
call_user_func($callable);
}
what would report the deprecation when actually calling the callable.
Not sure what to do regarding your given use case(s).
--
Christoph M. Becker
Unfortunately, those aren't the only places I see this happening and my
example is not a stand-alone case either.
I came across the above code sample ( is_callable('static::method') /
is_callable(['parent', __FUNCTION__]) with variable method calls) in a
number of different packages when testing a (PHPCompatibility) sniff I
am writing to detect the deprecation, so this code pattern looks to be
relatively common.
Some examples:
*
https://github.com/symfony/service-contracts/blob/bc0a2247c72d29241b5a06fb60dc1c9d9acf2a3a/ServiceSubscriberTrait.php#L39
*
https://github.com/mockery/mockery/blob/c10a5f6e06fc2470ab1822fa13fa2a7380f8fbac/library/Mockery/Mock.php#L960
*
https://github.com/simplepie/simplepie/blob/dacf0ed495d2e8fb306e526ca3f2a846af78a7c9/tests/oldtests/absolutize/RFC3986.5.4/base.php#L13
