Support switch on ::class

Author: VincentLanglet

src/Analyser/TypeSpecifier.php

@@ -1656,13 +1656,11 @@ private function findTypeExpressionsFromBinaryOperation(Scope $scope, Node\Expr\
 		if (
 			$leftType instanceof ConstantScalarType
 			&& !$rightExpr instanceof ConstFetch
-			&& !$rightExpr instanceof ClassConstFetch
 		) {
 			return [$binaryOperation->right, $leftType, $rightType];
 		} elseif (
 			$rightType instanceof ConstantScalarType
 			&& !$leftExpr instanceof ConstFetch
-			&& !$leftExpr instanceof ClassConstFetch
 		) {
 			return [$binaryOperation->left, $rightType, $leftType];
 		}
@@ -2061,6 +2059,16 @@ public function resolveEqual(Expr\BinaryOp\Equal $expr, Scope $scope, TypeSpecif
 			) {
 				return $this->specifyTypesInCondition($scope, new Expr\BinaryOp\Identical($expr->left, $expr->right), $context)->setRootExpr($expr);
 			}
+
+			if (
+				$context->true()
+				&& $exprNode instanceof ClassConstFetch
+				&& $exprNode->name instanceof Node\Identifier
+				&& strtolower($exprNode->name->toString()) === 'class'
+				&& $constantType->isString()->yes()
+			) {
+				return $this->specifyTypesInCondition($scope, new Expr\BinaryOp\Identical($expr->left, $expr->right), $context)->setRootExpr($expr);
+			}
 		}
 
 		$leftType = $scope->getType($expr->left);

tests/PHPStan/Analyser/nsrt/bug-13069.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Bug13069;
+
+use function PHPStan\Testing\assertType;
+
+interface ResourceInterface {}
+
+class Person implements ResourceInterface
+{
+	public function getName(): string { return 'Name'; }
+}
+
+class Account implements ResourceInterface
+{
+	public function getMail(): string  { return 'Mail'; }
+}
+
+function foo(?ResourceInterface $object = null): void
+{
+	switch ($object::class) {
+		case Person::class:
+			assertType(Person::class, $object);
+			echo $object->getName();
+			break;
+		case Account::class:
+			assertType(Account::class, $object);
+			echo $object->getMail();
+			break;
+	}
+}