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Error Identifier: classConstant.visibility

Every error reported by PHPStan has an error identifier. Here’s a list of all error identifiers. In PHPStan Pro you can see the error identifier next to each error and filter errors by their identifiers.

Code example #

<?php declare(strict_types = 1);

class Foo
{
    public const BAR = 1;
}

class Bar extends Foo
{
    private const BAR = 2;
}

Why is it reported? #

A class constant overrides a parent class or trait constant with a more restrictive visibility. PHP requires that an overriding constant must have the same or less restrictive visibility than the constant it overrides. For example, a public constant cannot be overridden as protected or private, and a protected constant cannot be overridden as private. Violating this rule causes a fatal error at runtime.

How to fix it #

Match or widen the visibility to be compatible with the parent:

 <?php declare(strict_types = 1);
 
 class Foo
 {
     public const BAR = 1;
 }

 class Bar extends Foo
 {
-    private const BAR = 2;
+    public const BAR = 2;
 }

Non-ignorable error #

This error cannot be ignored using @phpstan-ignore or the ignoreErrors configuration. Non-ignorable errors indicate code that would cause a crash or a fatal error at runtime, or a fundamental problem in the analysed code that must be addressed.

Rules that report this error #

  • PHPStan\Rules\Constants\OverridingConstantRule [1] [2]
  • PHPStan\Rules\Traits\ConflictingTraitConstantsRule [1] [2] [3] [4] [5] [6]

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