From 5041b0a0bbc5eb879561a266afa9018b9f777fbe Mon Sep 17 00:00:00 2001
From: Vincent Langlet <vincentlanglet@hotmail.fr>
Date: Sun, 5 Oct 2025 18:34:49 +0200
Subject: [PATCH] Improve is_resource inference

---
 stubs/typeCheckingFunctions.stub               |  2 +-
 ...ImpossibleCheckTypeFunctionCallRuleTest.php |  6 ++++++
 .../Rules/Comparison/data/bug-10394.php        | 18 ++++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 tests/PHPStan/Rules/Comparison/data/bug-10394.php

diff --git a/stubs/typeCheckingFunctions.stub b/stubs/typeCheckingFunctions.stub
index 4f06338125..f10609ee77 100644
--- a/stubs/typeCheckingFunctions.stub
+++ b/stubs/typeCheckingFunctions.stub
@@ -106,7 +106,7 @@ function is_long(mixed $value): bool
 
 /**
  * @phpstan-assert-if-true =resource $value
- * @return bool
+ * @return ($value is resource ? bool : false)
  */
 function is_resource(mixed $value): bool
 {
diff --git a/tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php b/tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php
index c795706ab9..3a0683d5ac 100644
--- a/tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php
+++ b/tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php
@@ -1094,6 +1094,12 @@ public function testBug12087c(): void
 		]);
 	}
 
+	public function testBug10394(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-10394.php'], []);
+	}
+
 	public function testBug9666(): void
 	{
 		$tipText = 'Because the type is coming from a PHPDoc, you can turn off this check by setting <fg=cyan>treatPhpDocTypesAsCertain: false</> in your <fg=cyan>%configurationFile%</>.';
diff --git a/tests/PHPStan/Rules/Comparison/data/bug-10394.php b/tests/PHPStan/Rules/Comparison/data/bug-10394.php
new file mode 100644
index 0000000000..e6aaafd247
--- /dev/null
+++ b/tests/PHPStan/Rules/Comparison/data/bug-10394.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Bug10394;
+
+class SomeClass
+{
+	private int $integer = 0;
+
+	public function __construct()
+	{
+		// try commenting this out!
+		$this->integer = 45;
+
+		if (is_resource($this->integer)) {
+			throw new \Exception('A resource??');
+		}
+	}
+}