PHP 8.4+ asymmetric property visibility

Group: Properties · Category: language · File: properties_asymmetric_visibility.php

A property that is publicly readable but privately writable must reject external assignment while still allowing external reads. References: - PHP language: asymmetric visibility

Analyzer results

Analyzer	Version	Result	Diagnostics
phan	6.0.10Phan 6.0.10 php-ast version 1.1.3 PHP version used to run Phan: 8.5.11	Pass	properties_asymmetric_visibility.php:29: Cannot modify private(set) property \Conformance\Tests\PropertiesAsymmetricVisibility\Counter->value defined at /Users/megurine/repo/php/php-typing-conformance/conformance/tests/properties_asymmetric_visibility.php:19 from /Users/megurine/repo/php/php-typing-conformance/conformance/tests/properties_asymmetric_visibility.php:29 [PhanAccessSetPropertyWrongContext]
phpstan	2.3.1PHPStan - PHP Static Analysis Tool 2.3.1	Pass reported Lv.2+	properties_asymmetric_visibility.php:29: Assign to private(set) property Conformance\Tests\PropertiesAsymmetricVisibility\Counter::$value. [reported-from-level=2] With strict-rules properties_asymmetric_visibility.php:29: Assign to private(set) property Conformance\Tests\PropertiesAsymmetricVisibility\Counter::$value.
psalm	6.20.0Psalm 6.20.0@804f03c0c183d149fcd4b8c7c0c9b3fbf836d34c next: 7.0.0-rc2	Pass (pzoom≠)	properties_asymmetric_visibility.php:29: Cannot modify private(set) property Conformance\Tests\PropertiesAsymmetricVisibility\Counter::$value [InaccessibleProperty] pzoom (Psalm port) No diagnostics from pzoom.
mago	1.57.0mago 1.57.0	Pass	properties_asymmetric_visibility.php:29: Cannot write to private property `$value` on class `Conformance\Tests\PropertiesAsymmetricVisibility\Counter`. [invalid-property-write]
mir	0.87.0mir 0.87.0	Pass	No diagnostics reported.
phpantom	0.11.1phpantom_lsp 0.11.1	Pass	No diagnostics reported.
intelephense	1.18.5intelephense 1.18.5	Pass	properties_asymmetric_visibility.php:29: Cannot modify property Conformance\Tests\PropertiesAsymmetricVisibility\Counter::$value from global scope. [P1056]
phpactor	2026.10.07.0Phpactor 2026.10.07.0	Pass	No diagnostics reported.
phpy	1.0.19409phpy 1.0.19409	Pass	properties_asymmetric_visibility.php:29: Member has public private(set) visibility and is not accessible from the current context.
qodana	262.10968.76PhpStorm 262.10968.76	Pass	No diagnostics reported.
noverify	0.5.5NoVerify, version 0.5.5: built on: 2025.04.22 14:36:46 OS: r-kuchinskas arm64 Commit: 4774b82f8adc53fbef38f95e97af4b953b4d1529	Pass	No diagnostics reported.
steins	0.1.8steins 0.1.8 (2026-09-21 revision 76306a9)	Pass	No diagnostics reported.
phpstan-strict	2.3.1PHPStan - PHP Static Analysis Tool 2.3.1	Pass	properties_asymmetric_visibility.php:29: Assign to private(set) property Conformance\Tests\PropertiesAsymmetricVisibility\Counter::$value.
psalm-next	7.0.0-rc2Psalm 7.0.0-rc2@20339e3fe5b8d03bcd8061030eb2a83ad50e5783	Pass	properties_asymmetric_visibility.php:29: Cannot modify private(set) property Conformance\Tests\PropertiesAsymmetricVisibility\Counter::$value [InaccessibleProperty]

Source

<?php

declare(strict_types=1);

namespace Conformance\Tests\PropertiesAsymmetricVisibility;

/**
 * PHP 8.4+ asymmetric property visibility.
 *
 * A property that is publicly readable but privately writable must reject
 * external assignment while still allowing external reads.
 *
 * References:
 * - PHP language: asymmetric visibility
 */

final class Counter
{
    public private(set) int $value = 0;

    public function increment(): void
    {
        $this->value++;
    }
}

$counter = new Counter();
echo $counter->value;
$counter->value = 10; // E?: external write to private(set) should be rejected // E<phpstan>: external write to private(set) should be rejected // E<phpstan-strict>: external write to private(set) should be rejected // E<mago>: external write to private(set) should be rejected // E<phan>: external write to private(set) should be rejected // E<intelephense>: external write to private(set) should be rejected