CallToConstructorStatementWithoutSideEffectsRule - report class with no constructor

Author: ondrejmirtes

Diff for: src/Rules/Methods/CallToConstructorStatementWithoutSideEffectsRule.php

@@ -43,7 +43,12 @@ public function processNode(Node $node, Scope $scope): array
 
 		$classReflection = $this->reflectionProvider->getClass($className);
 		if (!$classReflection->hasConstructor()) {
-			return [];
+			return [
+				RuleErrorBuilder::message(sprintf(
+					'Call to new %s() on a separate line has no effect.',
+					$classReflection->getDisplayName(),
+				))->identifier('new.resultUnused')->build(),
+			];
 		}
 
 		$constructor = $classReflection->getConstructor();

Diff for: tests/PHPStan/Rules/Methods/CallToConstructorStatementWithoutSideEffectsRuleTest.php

@@ -23,6 +23,14 @@ public function testRule(): void
 				'Call to Exception::__construct() on a separate line has no effect.',
 				6,
 			],
+			[
+				'Call to new PDOStatement() on a separate line has no effect.',
+				11,
+			],
+			[
+				'Call to new stdClass() on a separate line has no effect.',
+				12,
+			],
 			[
 				'Call to ConstructorStatementNoSideEffects\ConstructorWithPure::__construct() on a separate line has no effect.',
 				57,
@@ -31,6 +39,10 @@ public function testRule(): void
 				'Call to ConstructorStatementNoSideEffects\ConstructorWithPureAndThrowsVoid::__construct() on a separate line has no effect.',
 				58,
 			],
+			[
+				'Call to new ConstructorStatementNoSideEffects\NoConstructor() on a separate line has no effect.',
+				68,
+			],
 		]);
 	}
 

Diff for: tests/PHPStan/Rules/Methods/data/constructor-statement-no-side-effects.php

@@ -58,3 +58,12 @@ function(): void {
 	new ConstructorWithPureAndThrowsVoid();
 	new ConstructorWithPureAndThrowsException();
 };
+
+class NoConstructor
+{
+
+}
+
+function (): void {
+	new NoConstructor();
+};