interface.duplicate - Phpstan

Code example

This error is reported when the same interface is declared in multiple files within the analysed codebase:

php

// file1.php
<?php declare(strict_types = 1);

namespace App\Contracts;

interface Logger
{
	public function log(string $message): void;
}

php

// file2.php
<?php declare(strict_types = 1);

namespace App\Contracts;

interface Logger
{
	public function log(string $message): void;
}

Why is it reported?

The same interface is declared in multiple files within the registered stub files.

How to fix it

Remove the duplicate declaration and keep only one definition of the interface:

diff-php

-// Delete or rename the duplicate file src/Legacy/Logger.php

If both interfaces are needed, give them different names or place them in different namespaces:

diff-php

 <?php declare(strict_types = 1);

-namespace App\Contracts;
+namespace App\Legacy;

-interface Logger
+interface LegacyLogger
 {
 	public function log(string $message): void;
 }