ci(psalm): Add a checker against logical operators

build/psalm/LogicalOperatorChecker.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+use Psalm\CodeLocation;
+use Psalm\IssueBuffer;
+use Psalm\Plugin\EventHandler\AfterExpressionAnalysisInterface;
+use Psalm\Plugin\EventHandler\Event\AfterExpressionAnalysisEvent;
+
+class LogicalOperatorChecker implements AfterExpressionAnalysisInterface {
+	public static function afterExpressionAnalysis(AfterExpressionAnalysisEvent $event): ?bool {
+		$stmt = $event->getExpr();
+		if ($stmt instanceof PhpParser\Node\Expr\BinaryOp\LogicalAnd
+			|| $stmt instanceof PhpParser\Node\Expr\BinaryOp\LogicalOr) {
+			IssueBuffer::maybeAdd(
+				new \Psalm\Issue\UnrecognizedExpression(
+					'Logical binary operators AND and OR are not allowed in the Nextcloud codebase',
+					new CodeLocation($event->getStatementsSource()->getSource(), $stmt),
+				),
+				$event->getStatementsSource()->getSuppressedIssues(),
+			);
+		}
+		return null;
+	}
+}

psalm.xml

@@ -17,6 +17,7 @@
 	<plugins>
 		<plugin filename="build/psalm/AppFrameworkTainter.php" />
 		<plugin filename="build/psalm/AttributeNamedParameters.php" />
+		<plugin filename="build/psalm/LogicalOperatorChecker.php" />
 	</plugins>
 	<projectFiles>
 		<directory name="apps/admin_audit"/>