Use statement result of analysed anonymous class to inform about throw points and impure points

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -749,8 +749,15 @@ private function processStmtNode(
 		} elseif ($stmt instanceof Node\Stmt\Expression) {
 			$earlyTerminationExpr = $this->findEarlyTerminatingExpr($stmt->expr, $scope);
 			$hasAssign = false;
-			$result = $this->processExprNode($stmt, $stmt->expr, $scope, static function (Node $node, Scope $scope) use ($nodeCallback, &$hasAssign): void {
+			$currentScope = $scope;
+			$result = $this->processExprNode($stmt, $stmt->expr, $scope, static function (Node $node, Scope $scope) use ($nodeCallback, $currentScope, &$hasAssign): void {
 				$nodeCallback($node, $scope);
+				if ($scope->getAnonymousFunctionReflection() !== $currentScope->getAnonymousFunctionReflection()) {
+					return;
+				}
+				if ($scope->getFunction() !== $currentScope->getFunction()) {
+					return;
+				}
 				if (!$node instanceof VariableAssignNode && !$node instanceof PropertyAssignNode) {
 					return;
 				}
@@ -3152,7 +3159,31 @@ static function (): void {
 
 			} else {
 				$classReflection = $this->reflectionProvider->getAnonymousClassReflection($expr->class, $scope); // populates $expr->class->name
-				$this->processStmtNode($expr->class, $scope, $nodeCallback, StatementContext::createTopLevel());
+				$constructorResult = null;
+				$this->processStmtNode($expr->class, $scope, static function (Node $node, Scope $scope) use ($nodeCallback, $classReflection, &$constructorResult): void {
+					$nodeCallback($node, $scope);
+					if (!$node instanceof MethodReturnStatementsNode) {
+						return;
+					}
+					if ($constructorResult !== null) {
+						return;
+					}
+					$currentClassReflection = $node->getClassReflection();
+					if ($currentClassReflection->getName() !== $classReflection->getName()) {
+						return;
+					}
+					if (!$currentClassReflection->hasConstructor()) {
+						return;
+					}
+					if ($currentClassReflection->getConstructor()->getName() !== $node->getMethodReflection()->getName()) {
+						return;
+					}
+					$constructorResult = $node;
+				}, StatementContext::createTopLevel());
+				if ($constructorResult !== null) {
+					$throwPoints = array_merge($throwPoints, $constructorResult->getStatementResult()->getThrowPoints());
+					$impurePoints = array_merge($impurePoints, $constructorResult->getImpurePoints());
+				}
 				if ($classReflection->hasConstructor()) {
 					$constructorReflection = $classReflection->getConstructor();
 					$parametersAcceptor = ParametersAcceptorSelector::selectFromArgs(

src/Rules/DeadCode/BetterNoopRule.php

@@ -93,10 +93,14 @@ public function processNode(Node $node, Scope $scope): array
 			}
 		}
 
+		if ($expr instanceof Node\Expr\New_ && $expr->class instanceof Node\Name) {
+			// handled by CallToConstructorStatementWithoutSideEffectsRule
+			return [];
+		}
+
 		if (
 			$expr instanceof Node\Expr\NullsafeMethodCall
 			|| $expr instanceof Node\Expr\MethodCall
-			|| $expr instanceof Node\Expr\New_
 			|| $expr instanceof Node\Expr\StaticCall
 		) {
 			// handled by *WithoutSideEffectsRule rules

tests/PHPStan/Analyser/data/AnonymousClassesWithComments.php

@@ -1,7 +1,7 @@
 <?php
 
 // Test comment
-new class () {
+$a = new class () {
 
 	public function doFoo(): void
 	{
@@ -10,8 +10,7 @@ public function doFoo(): void
 
 };
 
-/* Test comment */
-new class () {
+$a = /* Test comment */ new class () {
 
 	public function doFoo(): void
 	{
@@ -20,8 +19,7 @@ public function doFoo(): void
 
 };
 
-/** Test comment */
-new class () {
+$a = /** Test comment */ new class () {
 
 	public function doFoo(): void
 	{

tests/PHPStan/Analyser/data/anonymous-class-with-inherited-constructor.php

@@ -14,7 +14,7 @@ public function __construct(int $i, int $j)
 }
 
 function () {
-	new class (1, 2) extends Foo
+	$a = new class (1, 2) extends Foo
 	{
 
 	};
@@ -30,7 +30,7 @@ final public function __construct(int $i, int $j)
 }
 
 function () {
-	new class (1, 2) extends Bar
+	$a = new class (1, 2) extends Bar
 	{
 
 	};

tests/PHPStan/Analyser/data/bug-6442.php

@@ -17,7 +17,7 @@ class B extends A
 	use T;
 }
 
-new class() extends B
+$a = new class() extends B
 {
 	use T;
 };

tests/PHPStan/Analyser/traits/AnonymousClassUsingTrait.php

@@ -2,7 +2,7 @@
 
 namespace AnonymousTraitClass;
 
-new class implements FooInterface {
+$a = new class implements FooInterface {
 
 	use TraitWithTypeSpecification;
 

tests/PHPStan/Rules/DeadCode/BetterNoopRuleTest.php

@@ -132,6 +132,14 @@ public function testRuleImpurePoints(): void
 				'Expression "$b()" on a separate line does not do anything.',
 				59,
 			],
+			[
+				'Expression "new class…" on a separate line does not do anything.',
+				98,
+			],
+			[
+				'Expression "new class…" on a separate line does not do anything.',
+				104,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/DeadCode/data/noop-impure-points.php

@@ -83,4 +83,35 @@ public function doFunctionWithByRef(bool $b, array $a): void
 		$func($a, 1);
 	}
 
+	public function anonymousClassWithSideEffect(): void
+	{
+		new class () {
+			public function __construct()
+			{
+				echo '1';
+			}
+		};
+	}
+
+	public function anonymousClassWithoutConstructor(): void
+	{
+		new class () {
+		};
+	}
+
+	public function anonymousClassWithPureConstructor(): void
+	{
+		new class () {
+
+			/** @var int */
+			private $i;
+
+			public function __construct()
+			{
+				$this->i = 1;
+			}
+
+		};
+	}
+
 }