Bleeding edge - report top-level xor because that's probably not what…

… the user intended to do
phpstan · Dec 7, 2023 · a1fffb3 · a1fffb3
1 parent 3b011f6
commit a1fffb3
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Showing 4 changed files with 26 additions and 4 deletions.
diff --git a/conf/config.level4.neon b/conf/config.level4.neon
@@ -3,7 +3,6 @@ includes:
 
 rules:
 	- PHPStan\Rules\Arrays\DeadForeachRule
-	- PHPStan\Rules\DeadCode\NoopRule
 	- PHPStan\Rules\DeadCode\UnreachableStatementRule
 	- PHPStan\Rules\DeadCode\UnusedPrivateConstantRule
 	- PHPStan\Rules\DeadCode\UnusedPrivateMethodRule
@@ -68,6 +67,13 @@ services:
 		tags:
 			- phpstan.rules.rule
 
+	-
+		class: PHPStan\Rules\DeadCode\NoopRule
+		arguments:
+			logicalXor: %featureToggles.logicalXor%
+		tags:
+			- phpstan.rules.rule
+
 	-
 		class: PHPStan\Rules\DeadCode\UnusedPrivatePropertyRule
 		arguments:

diff --git a/src/Rules/DeadCode/NoopRule.php b/src/Rules/DeadCode/NoopRule.php
@@ -15,7 +15,7 @@
 class NoopRule implements Rule
 {
 
-	public function __construct(private ExprPrinter $exprPrinter)
+	public function __construct(private ExprPrinter $exprPrinter, private bool $logicalXor)
 	{
 	}
 
@@ -36,6 +36,15 @@ public function processNode(Node $node, Scope $scope): array
 		) {
 			$expr = $expr->expr;
 		}
+		if ($this->logicalXor && $expr instanceof Node\Expr\BinaryOp\LogicalXor) {
+			return [
+				RuleErrorBuilder::message(
+					'Unused result of "xor" operator.',
+				)->line($expr->getLine())
+					->tip('This operator has unexpected precedence, try disambiguating the logic with parentheses ().')
+					->build(),
+			];
+		}
 		if (
 			!$expr instanceof Node\Expr\Variable
 			&& !$expr instanceof Node\Expr\PropertyFetch

diff --git a/tests/PHPStan/Rules/DeadCode/NoopRuleTest.php b/tests/PHPStan/Rules/DeadCode/NoopRuleTest.php
@@ -15,7 +15,7 @@ class NoopRuleTest extends RuleTestCase
 
 	protected function getRule(): Rule
 	{
-		return new NoopRule(new ExprPrinter(new Printer()));
+		return new NoopRule(new ExprPrinter(new Printer()), true);
 	}
 
 	public function testRule(): void
@@ -77,6 +77,11 @@ public function testRule(): void
 				'Expression "(string) 1" on a separate line does not do anything.',
 				30,
 			],
+			[
+				'Unused result of "xor" operator.',
+				32,
+				'This operator has unexpected precedence, try disambiguating the logic with parentheses ().',
+			],
 		]);
 	}
 

diff --git a/tests/PHPStan/Rules/DeadCode/data/noop.php b/tests/PHPStan/Rules/DeadCode/data/noop.php
@@ -2,7 +2,7 @@
 
 namespace DeadCodeNoop;
 
-function (stdClass $foo) {
+function (stdClass $foo, bool $a, bool $b) {
 	$foo->foo();
 
 	$arr = [];
@@ -28,4 +28,6 @@ function (stdClass $foo) {
 	Foo::TEST;
 
 	(string) 1;
+
+	$r = $a xor $b;
 };