• PHPStan

To use this extension, require it in Composer:

composer require --dev phpstan/phpstan-deprecation-rules

If you also install phpstan/extension-installer then you're all set!

includes:
    - vendor/phpstan/phpstan-deprecation-rules/rules.neon

This extension emits deprecation warnings on code, which uses properties/functions/methods/classes which are annotated as @deprecated.

In case you don't own the code which you want to be considered deprecated, use PHPStan Stub Files to declare deprecations for vendor files like:

/** @deprecated */
class ThirdPartyClass {}

You can implement extensions to support even e.g. custom #[MyDeprecated] attribute. Learn more.

Usage of deprecated code is not reported in code that is also deprecated:

/** @deprecated */
function doFoo(): void
{
    // not reported:
    anotherDeprecatedFunction();
}

If you have a different way of marking code that calls deprecated symbols on purpose and you don't want these calls to be reported either, you can write an extension by implementing the DeprecatedScopeResolver interface.

For example if you mark your PHPUnit tests that test deprecated code with @group legacy, you can implement the extension this way:

class GroupLegacyScopeResolver implements DeprecatedScopeResolver
{
	public function isScopeDeprecated(Scope $scope): bool
	{
		$function = $scope->getFunction();
		return $function !== null
			&& $function->getDocComment() !== null
			&& strpos($function->getDocComment(), '@group legacy') !== false;
	}
}

And register it in your configuration file:

services:
	-
		class: GroupLegacyScopeResolver
		tags:
			- phpstan.deprecations.deprecatedScopeResolver

Learn more about Scope, a core concept for implementing custom PHPStan extensions.