Add regression tests for #9455 and #5207

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ondrejmirtes

tests/PHPStan/Analyser/nsrt/bug-5207.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Bug5207;
+
+use function PHPStan\Testing\assertType;
+
+abstract class HelloWorld
+{
+
+	abstract public function getChild(): ?HelloWorld;
+
+	public function sayHello(): HelloWorld
+	{
+		$foo = null !== $this->getChild();
+
+		if ($foo) {
+			assertType(HelloWorld::class, $this->getChild());
+			return $this->getChild();
+		}
+
+		throw new \Exception();
+	}
+
+}

tests/PHPStan/Analyser/nsrt/bug-9455.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Bug9455;
+
+use function PHPStan\Testing\assertType;
+
+class A {
+	public function __construct(private int $id) {}
+
+	public function getId(): int
+	{
+		return $this->id;
+	}
+}
+
+class B {
+	public function __construct(private int $id, private ?A $a = null) {}
+
+	public function getId(): int
+	{
+		return $this->id;
+	}
+
+	public function getA(): ?A
+	{
+		return $this->a;
+	}
+}
+
+class HelloWorld
+{
+
+	public function testFails(B $b): void
+	{
+		$hasA = $b->getA() !== null;
+
+		if ($hasA) {
+			assertType(A::class, $b->getA());
+			echo $b->getA()->getId();
+		}
+	}
+
+	public function testSucceeds(B $b): void
+	{
+		if ($b->getA() !== null) {
+			assertType(A::class, $b->getA());
+			echo $b->getA()->getId();
+		}
+	}
+
+}