Coverage not working on closures in PHPDBG

[Ocramius]

Q	A
php-code-coverage version	9.2.17
PHP version	8.1.10
Driver	PHPDBG
PCOV version (if used)	1.0.11
Xdebug version (if used)
Installation Method	Composer
Usage Method	PHPUnit
PHPUnit version (if used)	9.5.25

As investigated in infection/infection#1736, coverage for closures doesn't seem to be picked up correctly, when using PHPDBG.

Specifically, PCOV works as expected:

A coverage report done with phpdbg -qrr will instead produce partial coverage:

Reproducible example

<?php

declare(strict_types=1);

final class Foo
{
    /** @return callable(): int */
    function make(): callable
    {
        return static function (): int {
            return 1;
        };
    }
}

<?php

declare(strict_types=1);

require_once __DIR__ . '/../../src/Foo.php';

/** @covers Foo */
final class FooTest extends \PHPUnit\Framework\TestCase
{
    function testClosure(): void
    {
        self::assertSame(1, (new Foo())->make()());
    }
}

PHPDBG output

❯ phpdbg -qrr ./vendor/bin/phpunit --coverage-html=coverage --filter=Foo
PHPUnit 9.5.25 #StandWithUkraine

.                                                                   1 / 1 (100%)

Time: 00:00.140, Memory: 50.00 MB

OK (1 test, 1 assertion)

Generating code coverage report in HTML format ... done [00:00.812]

PCOV output

❯ ./vendor/bin/phpunit --coverage-html=coverage --filter=Foo
PHPUnit 9.5.25 #StandWithUkraine

.                                                                   1 / 1 (100%)

Time: 00:00.053, Memory: 40.00 MB

OK (1 test, 1 assertion)

Generating code coverage report in HTML format ... done [00:00.708]

PHPDBG + PCOV = 💥

Note: running phpdbg with pcov installed will lead to a segfault:

❯ phpdbg -qrr ./vendor/bin/phpunit --coverage-html=coverage --filter=Foo
PHPUnit 9.5.25 #StandWithUkraine

Segmentation fault (core dumped)

[Ocramius]

Note: I reported this here, because I don't know if the problem is in phpdbg or in phpunit/php-code-coverage.

I don't really know the underlying protocol, so any help is welcome 👍

[sebastianbergmann]

I have never used PHPDBG in production and can only recommend to not use it.

Use PCOV if you only need line coverage and Xdebug if you also want branch and path coverage.

The code coverage functionality provided by PHPDBG is not really maintained, as far as I know. To be honest, the right thing to do would probably be to remove support for it from this library.

[Ocramius]

Makes sense: I used phpdbg because it comes with php-src, and I didn't want to add more dependencies to my stack (in general), but I can live with this decision, and adapt to it long-term 👍

[sebastianbergmann]

Removed support for PHPDBG in c304be7 for php-code-coverage v10 (to be released alongside PHPUnit 10 in February 2023).

[Ocramius]

That was quick and decisive 💪

I'll make sure to upgrade my downstream projects before PHPUnit 10 hits us :)