Do not report unused private methods/properties in traits

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -585,6 +585,9 @@ private function processStmtNode(
 				if (!$scope->isInClass()) {
 					throw new \PHPStan\ShouldNotHappenException();
 				}
+				if ($scope->isInTrait()) {
+					return;
+				}
 				if ($scope->getClassReflection()->getName() !== $classReflection->getName()) {
 					return;
 				}

tests/PHPStan/Rules/DeadCode/data/unused-private-method.php

@@ -121,3 +121,30 @@ public function doBar(string $s)
 	}
 
 }
+
+trait FooTrait
+{
+
+	private function doFoo()
+	{
+
+	}
+
+	private function doBar()
+	{
+
+	}
+
+	public function doBaz()
+	{
+		$this->doFoo();
+	}
+
+}
+
+class UsingFooTrait
+{
+
+	use FooTrait;
+
+}

tests/PHPStan/Rules/DeadCode/data/unused-private-property.php

@@ -154,3 +154,29 @@ class TextExtension
 	private $used;
 
 }
+
+trait FooTrait
+{
+
+	private $prop1;
+
+	private $prop2;
+
+	public function doFoo()
+	{
+		echo $this->prop1;
+	}
+
+	public function setFoo($prop1)
+	{
+		$this->prop1 = $prop1;
+	}
+
+}
+
+class ClassUsingTrait
+{
+
+	use FooTrait;
+
+}