From 3e5cd7fba7655307cbc758142e265b475a106a57 Mon Sep 17 00:00:00 2001
From: Ondrej Mirtes <ondrej@mirtes.cz>
Date: Sat, 17 Aug 2019 13:57:35 +0200
Subject: [PATCH] InstantiationRule - test new static() in cases where it's
 possible

---
 src/Rules/Classes/InstantiationRule.php       | 17 ++++++-
 .../Rules/Classes/InstantiationRuleTest.php   | 12 +++++
 .../Rules/Classes/data/instantiation.php      | 50 +++++++++++++++++++
 3 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/src/Rules/Classes/InstantiationRule.php b/src/Rules/Classes/InstantiationRule.php
index 6ae280b9d8..cf8afad37b 100644
--- a/src/Rules/Classes/InstantiationRule.php
+++ b/src/Rules/Classes/InstantiationRule.php
@@ -7,6 +7,7 @@
 use PHPStan\Analyser\Scope;
 use PHPStan\Broker\Broker;
 use PHPStan\Reflection\ParametersAcceptorSelector;
+use PHPStan\Reflection\Php\PhpMethodReflection;
 use PHPStan\Rules\ClassCaseSensitivityCheck;
 use PHPStan\Rules\ClassNameNodePair;
 use PHPStan\Rules\FunctionCallParametersCheck;
@@ -72,7 +73,21 @@ private function checkClassName(string $class, Node $node, Scope $scope): array
 					sprintf('Using %s outside of class scope.', $class),
 				];
 			}
-			return [];
+
+			$classReflection = $scope->getClassReflection();
+			if (!$classReflection->isFinal()) {
+				if (!$classReflection->hasConstructor()) {
+					return [];
+				}
+
+				$constructor = $classReflection->getConstructor();
+				if (!$constructor->getPrototype()->getDeclaringClass()->isInterface()) {
+					$isFinal = $constructor instanceof PhpMethodReflection && $constructor->isFinal();
+					if (!$isFinal) {
+						return [];
+					}
+				}
+			}
 		} elseif ($lowercasedClass === 'self') {
 			if (!$scope->isInClass()) {
 				return [
diff --git a/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php b/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php
index 70d40a1a86..a164665829 100644
--- a/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php
+++ b/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php
@@ -155,6 +155,18 @@ public function testInstantiation(): void
 					'Instantiated class UndefinedClass3 not found.',
 					176,
 				],
+				[
+					'Class TestInstantiation\FinalClass does not have a constructor and must be instantiated without any parameters.',
+					187,
+				],
+				[
+					'Class TestInstantiation\ClassWithFinalConstructor constructor invoked with 0 parameters, 1 required.',
+					203,
+				],
+				[
+					'Class TestInstantiation\ConstructorComingFromAnInterface constructor invoked with 0 parameters, 1 required.',
+					226,
+				],
 			]
 		);
 	}
diff --git a/tests/PHPStan/Rules/Classes/data/instantiation.php b/tests/PHPStan/Rules/Classes/data/instantiation.php
index 143fc2a2be..a9bf4be074 100644
--- a/tests/PHPStan/Rules/Classes/data/instantiation.php
+++ b/tests/PHPStan/Rules/Classes/data/instantiation.php
@@ -177,3 +177,53 @@ public static function doFoo(string $key): void
 	}
 
 }
+
+final class FinalClass
+{
+
+	public function doFoo()
+	{
+		new static();
+		new static(1);
+	}
+
+}
+
+class ClassWithFinalConstructor
+{
+
+	final public function __construct(int $i)
+	{
+
+	}
+
+	public function doFoo()
+	{
+		new static(1);
+		new static();
+	}
+
+}
+
+interface InterfaceWithConstructor
+{
+
+	public function __construct(int $i);
+
+}
+
+class ConstructorComingFromAnInterface implements InterfaceWithConstructor
+{
+
+	public function __construct(int $i)
+	{
+
+	}
+
+	public function doFoo()
+	{
+		new static(1);
+		new static();
+	}
+
+}