From 9544f8a6b52dbd6068800bbfc5bdaf67fe04a8c2 Mon Sep 17 00:00:00 2001
From: Ondrej Mirtes <ondrej@mirtes.cz>
Date: Mon, 13 May 2024 09:51:03 +0200
Subject: [PATCH] Do not complain about `impure(Function|Method).pure` if it
 has `@phpstan-assert` tags

---
 src/Rules/Pure/FunctionPurityCheck.php        |  6 +++++-
 tests/PHPStan/Rules/Pure/data/pure-method.php | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/Rules/Pure/FunctionPurityCheck.php b/src/Rules/Pure/FunctionPurityCheck.php
index 9bd7046986..4e294dc0fe 100644
--- a/src/Rules/Pure/FunctionPurityCheck.php
+++ b/src/Rules/Pure/FunctionPurityCheck.php
@@ -89,7 +89,11 @@ public function check(
 					->build();
 			}
 		} elseif ($isPure->no()) {
-			if (count($impurePoints) === 0) {
+			if (
+				count($throwPoints) === 0
+				&& count($impurePoints) === 0
+				&& count($functionReflection->getAsserts()->getAll()) === 0
+			) {
 				$errors[] = RuleErrorBuilder::message(sprintf(
 					'%s is marked as impure but does not have any side effects.',
 					$functionDescription,
diff --git a/tests/PHPStan/Rules/Pure/data/pure-method.php b/tests/PHPStan/Rules/Pure/data/pure-method.php
index 2b91f7ea69..bcaa939b76 100644
--- a/tests/PHPStan/Rules/Pure/data/pure-method.php
+++ b/tests/PHPStan/Rules/Pure/data/pure-method.php
@@ -360,3 +360,18 @@ private function doBaz(): void
 	}
 
 }
+
+class AssertingImpureVoidMethod
+{
+
+	/**
+	 * @param mixed $value
+	 * @phpstan-assert array $value
+	 * @phpstan-impure
+	 */
+	public function assertSth($value): void
+	{
+
+	}
+
+}