Fix phpstan/phpstan#9455: Bug: False report Cannot call method getId() on A|null (#5447)

Co-authored-by: staabm <120441+staabm@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: 3 people

src/Analyser/ExprHandler/AssignHandler.php

@@ -865,6 +865,8 @@ private function processSureTypesForConditionalExpressionsAfterAssign(Scope $sco
 				!$expr instanceof PropertyFetch
 				&& !$expr instanceof ArrayDimFetch
 				&& !$expr instanceof FuncCall
+				&& !$expr instanceof MethodCall
+				&& !$expr instanceof Expr\StaticCall
 			) {
 				continue;
 			}
@@ -904,6 +906,8 @@ private function processSureNotTypesForConditionalExpressionsAfterAssign(Scope $
 				!$expr instanceof PropertyFetch
 				&& !$expr instanceof ArrayDimFetch
 				&& !$expr instanceof FuncCall
+				&& !$expr instanceof MethodCall
+				&& !$expr instanceof Expr\StaticCall
 			) {
 				continue;
 			}

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

@@ -0,0 +1,81 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug5207;
+
+use function PHPStan\Testing\assertType;
+
+abstract class HelloWorld {
+	abstract public function getChild(): ?HelloWorld;
+
+	public function sayHello(): void {
+		$foo = null !== $this->getChild();
+		if ($foo) {
+			assertType('Bug5207\HelloWorld', $this->getChild());
+		}
+	}
+
+	public function sayHelloInline(): void {
+		if (null !== $this->getChild()) {
+			assertType('Bug5207\HelloWorld', $this->getChild());
+		}
+	}
+}
+
+abstract class StaticWorld {
+	abstract public static function getChild(): ?StaticWorld;
+
+	public static function sayHello(): void {
+		$foo = null !== static::getChild();
+		if ($foo) {
+			assertType('Bug5207\StaticWorld', static::getChild());
+		}
+	}
+
+	public static function sayHelloInline(): void {
+		if (null !== static::getChild()) {
+			assertType('Bug5207\StaticWorld', static::getChild());
+		}
+	}
+}
+
+abstract class ImpureStaticWorld {
+	/**
+	 * @phpstan-impure
+	 */
+	abstract public static function getChild(): ?ImpureStaticWorld;
+
+	public static function sayHello(): void {
+		$foo = null !== static::getChild();
+		if ($foo) {
+			assertType('Bug5207\ImpureStaticWorld|null', static::getChild());
+		}
+	}
+
+	public static function sayHelloInline(): void {
+		if (null !== static::getChild()) {
+			assertType('Bug5207\ImpureStaticWorld|null', static::getChild());
+		}
+	}
+}
+
+abstract class ImpureWorld {
+	/**
+	 * @phpstan-impure
+	 */
+	abstract public function getChild(): ?ImpureWorld;
+
+	public function sayHello(): void {
+		$foo = null !== $this->getChild();
+		if ($foo) {
+			assertType('Bug5207\ImpureWorld|null', $this->getChild());
+		}
+	}
+
+	public function sayHelloInline(): void {
+		if (null !== $this->getChild()) {
+			assertType('Bug5207\ImpureWorld|null', $this->getChild());
+		}
+	}
+}

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

@@ -0,0 +1,84 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+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(): void
+	{
+		$a = new A(1);
+		$b = new B(1, $a);
+
+		$hasA = $b->getA() !== null;
+
+		if($hasA) {
+			assertType('Bug9455\A', $b->getA());
+		}
+	}
+
+	public function testSucceeds(): void
+	{
+		$a = new A(1);
+		$b = new B(1, $a);
+
+		if($b->getA() !== null) {
+			assertType('Bug9455\A', $b->getA());
+		}
+	}
+}
+
+class C {
+	/**
+	 * @phpstan-impure
+	 */
+	public function getA(): ?A {
+		return rand(0, 1) ? new A(1) : null;
+	}
+}
+
+class ImpureTest
+{
+	public function testImpureMethodNotNarrowed(): void
+	{
+		$c = new C();
+
+		$hasA = $c->getA() !== null;
+
+		if($hasA) {
+			assertType('Bug9455\A|null', $c->getA());
+		}
+	}
+
+	public function testImpureMethodInline(): void
+	{
+		$c = new C();
+
+		if($c->getA() !== null) {
+			assertType('Bug9455\A|null', $c->getA());
+		}
+	}
+}