Added regression test

Author: staabm

tests/PHPStan/Rules/Properties/MissingReadOnlyPropertyAssignRuleTest.php

@@ -16,6 +16,8 @@
 class MissingReadOnlyPropertyAssignRuleTest extends RuleTestCase
 {
 
+	private bool $shouldNarrowMethodScopeFromConstructor = false;
+
 	protected function getRule(): Rule
 	{
 		return new MissingReadOnlyPropertyAssignRule(
@@ -31,6 +33,11 @@ protected function getRule(): Rule
 		);
 	}
 
+	public function shouldNarrowMethodScopeFromConstructor(): bool
+	{
+		return $this->shouldNarrowMethodScopeFromConstructor;
+	}
+
 	protected function getReadWritePropertiesExtensions(): array
 	{
 		return [
@@ -375,6 +382,16 @@ public function testBug9863(): void
 		]);
 	}
 
+	public function testBug10048(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('Test requires PHP 8.1.');
+		}
+
+		$this->shouldNarrowMethodScopeFromConstructor = true;
+		$this->analyse([__DIR__ . '/data/bug-10048.php'], []);
+	}
+
 	public function testBug9864(): void
 	{
 		if (PHP_VERSION_ID < 80100) {

tests/PHPStan/Rules/Properties/data/bug-10048.php

@@ -0,0 +1,26 @@
+<?php declare(strict_types = 1);
+
+namespace Bug10048;
+
+class Foo {
+	private readonly string $bar;
+	private readonly \Closure $callback;
+	public function __construct() {
+		$this->bar = "hi";
+		$this->useBar();
+		echo $this->bar;
+		$this->callback = function() {
+			$this->useBar();
+		};
+	}
+
+	private function useBar(): void {
+		echo $this->bar;
+	}
+
+	public function useCallback(): void {
+		call_user_func($this->callback);
+	}
+}
+
+(new Foo())->useCallback();