StaticVarsChecker.php

<?php

declare(strict_types=1);

/**
 * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

use PhpParser\Node\Stmt\Property;
use Psalm\CodeLocation;
use Psalm\IssueBuffer;
use Psalm\Plugin\EventHandler\AfterClassLikeVisitInterface;
use Psalm\Plugin\EventHandler\AfterStatementAnalysisInterface;
use Psalm\Plugin\EventHandler\Event\AfterClassLikeVisitEvent;
use Psalm\Plugin\EventHandler\Event\AfterStatementAnalysisEvent;

/**
 * Complains about static property in classes and static vars in methods
 */
class StaticVarsChecker implements AfterClassLikeVisitInterface, AfterStatementAnalysisInterface {
	public static function afterClassLikeVisit(AfterClassLikeVisitEvent $event): void {
		$classLike = $event->getStmt();
		$statementsSource = $event->getStatementsSource();

		foreach ($classLike->stmts as $stmt) {
			if ($stmt instanceof Property) {
				if ($stmt->isStatic()) {
					IssueBuffer::maybeAdd(
						// ImpureStaticProperty is close enough, all static properties are impure to my eyes
						new \Psalm\Issue\ImpureStaticProperty(
							'Static property should not be used as they do not follow requests lifecycle',
							new CodeLocation($statementsSource, $stmt),
						)
					);
				}
			}
		}
	}

	public static function afterStatementAnalysis(AfterStatementAnalysisEvent $event): ?bool {
		$stmt = $event->getStmt();
		if ($stmt instanceof PhpParser\Node\Stmt\Static_) {
			IssueBuffer::maybeAdd(
				// Same logic
				new \Psalm\Issue\ImpureStaticVariable(
					'Static var should not be used as they do not follow requests lifecycle and are hard to reset',
					new CodeLocation($event->getStatementsSource(), $stmt),
				)
			);
		}
		return null;
	}
}