Error Identifier: interface.duplicateProperty

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);

interface Foo
{
	public string $name { get; }
	public string $name { get; }
}

Why is it reported? #

The interface declares the same property name more than once. Since PHP 8.4, interfaces can have property declarations with hooks. PHP does not allow redeclaring a property within the same interface body. This will cause a fatal error at runtime.

How to fix it #

Remove the duplicate property declaration or rename it:

 <?php declare(strict_types = 1);
 
 interface Foo
 {
 	public string $name { get; }
-	public string $name { get; }
+	public string $label { get; }
 }

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\Classes\DuplicateDeclarationRule [1] [2]

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