From 25bacb3e671d045dafb2eddcbb208578aa4f9e4c Mon Sep 17 00:00:00 2001
From: USAMI Kenta <tadsan@zonu.me>
Date: Wed, 8 Jul 2026 18:53:45 +0900
Subject: [PATCH] Add named argument tests for @pure-unless-callable-is-impure

---
 .../Rules/Pure/PureFunctionRuleTest.php       |  51 +++++++
 ...re-unless-callable-is-impure-named-arg.php | 138 ++++++++++++++++++
 2 files changed, 189 insertions(+)
 create mode 100644 tests/PHPStan/Rules/Pure/data/pure-unless-callable-is-impure-named-arg.php

diff --git a/tests/PHPStan/Rules/Pure/PureFunctionRuleTest.php b/tests/PHPStan/Rules/Pure/PureFunctionRuleTest.php
index 173ab215ba..1a4d3c3fbb 100644
--- a/tests/PHPStan/Rules/Pure/PureFunctionRuleTest.php
+++ b/tests/PHPStan/Rules/Pure/PureFunctionRuleTest.php
@@ -296,6 +296,57 @@ public function testPureUnlessCallableIsImpure(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.0.0')]
+	public function testPureUnlessCallableIsImpureNamedArgs(): void
+	{
+		$this->analyse([__DIR__ . '/data/pure-unless-callable-is-impure-named-arg.php'], [
+			[
+				'Impure call to function PureUnlessCallableIsImpureNamedArg\myMap() in pure function PureUnlessCallableIsImpureNamedArg\pureCallingUserlandWithImpureCallbackByName().',
+				61,
+			],
+			[
+				'Impure echo in pure function PureUnlessCallableIsImpureNamedArg\pureCallingUserlandWithImpureCallbackByName().',
+				62,
+			],
+			[
+				'Possibly impure call to a callable in pure function PureUnlessCallableIsImpureNamedArg\pureCallingUserlandWithOpaqueCallbackByName().',
+				75,
+			],
+			[
+				'Possibly impure call to function PureUnlessCallableIsImpureNamedArg\myMap() in pure function PureUnlessCallableIsImpureNamedArg\pureCallingUserlandWithOpaqueCallbackByName().',
+				75,
+			],
+			[
+				'Impure call to function array_map() in pure function PureUnlessCallableIsImpureNamedArg\pureWithImpureCallbackByName().',
+				85,
+			],
+			[
+				'Impure echo in pure function PureUnlessCallableIsImpureNamedArg\pureWithImpureCallbackByName().',
+				86,
+			],
+			[
+				'Possibly impure call to a callable in pure function PureUnlessCallableIsImpureNamedArg\pureWithOpaqueCallbackByName().',
+				99,
+			],
+			[
+				'Possibly impure call to function array_map() in pure function PureUnlessCallableIsImpureNamedArg\pureWithOpaqueCallbackByName().',
+				99,
+			],
+			[
+				'Impure call to function PureUnlessCallableIsImpureNamedArg\myMap() in pure function PureUnlessCallableIsImpureNamedArg\pureCallingUserlandWithImpureCallbackShuffled().',
+				121,
+			],
+			[
+				'Impure echo in pure function PureUnlessCallableIsImpureNamedArg\pureCallingUserlandWithImpureCallbackShuffled().',
+				122,
+			],
+			[
+				'Impure call to method PureUnlessCallableIsImpureNamedArg\Mapper::map() in pure function PureUnlessCallableIsImpureNamedArg\pureCallingMethodWithImpureCallbackByName().',
+				134,
+			],
+		]);
+	}
+
 	#[RequiresPhp('>= 8.4.0')]
 	public function testPureUnlessCallableIsImpurePhp84(): void
 	{
diff --git a/tests/PHPStan/Rules/Pure/data/pure-unless-callable-is-impure-named-arg.php b/tests/PHPStan/Rules/Pure/data/pure-unless-callable-is-impure-named-arg.php
new file mode 100644
index 0000000000..20ebcd5dea
--- /dev/null
+++ b/tests/PHPStan/Rules/Pure/data/pure-unless-callable-is-impure-named-arg.php
@@ -0,0 +1,138 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace PureUnlessCallableIsImpureNamedArg;
+
+/**
+ * @param callable(int): int $f
+ * @param array<int> $arr
+ * @return array<int>
+ * @pure-unless-callable-is-impure $f
+ */
+function myMap(callable $f, array $arr): array
+{
+	$result = [];
+	foreach ($arr as $i => $v) {
+		$result[$i] = $f($v);
+	}
+
+	return $result;
+}
+
+class Mapper
+{
+
+	/**
+	 * @param callable(int): int $f
+	 * @param array<int> $arr
+	 * @return array<int>
+	 * @pure-unless-callable-is-impure $f
+	 */
+	public function map(callable $f, array $arr): array
+	{
+		$result = [];
+		foreach ($arr as $i => $v) {
+			$result[$i] = $f($v);
+		}
+
+		return $result;
+	}
+
+}
+
+/**
+ * @param array<int> $arr
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureCallingUserlandWithPureCallbackByName(array $arr): array
+{
+	return myMap(f: static fn (int $x): int => $x * 2, arr: $arr);
+}
+
+/**
+ * @param array<int> $arr
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureCallingUserlandWithImpureCallbackByName(array $arr): array
+{
+	return myMap(f: static function (int $x): int {
+		echo $x;
+		return $x * 2;
+	}, arr: $arr);
+}
+
+/**
+ * @param array<int> $arr
+ * @param callable(int): int $cb
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureCallingUserlandWithOpaqueCallbackByName(array $arr, callable $cb): array
+{
+	return myMap(f: $cb, arr: $arr);
+}
+
+/**
+ * @param array<int> $arr
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureWithImpureCallbackByName(array $arr): array
+{
+	return array_map(callback: static function (int $x): int {
+		echo $x;
+		return $x * 2;
+	}, array: $arr);
+}
+
+/**
+ * @param array<int> $arr
+ * @param callable(int): int $cb
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureWithOpaqueCallbackByName(array $arr, callable $cb): array
+{
+	return array_map(callback: $cb, array: $arr);
+}
+
+/**
+ * @param array<int> $arr
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureCallingUserlandWithPureCallbackShuffled(array $arr): array
+{
+	// Arguments are passed in shuffled order using names, so name-based matching
+	// (not positional matching) determines which argument is judged for purity.
+	return myMap(arr: $arr, f: static fn (int $x): int => $x * 2);
+}
+
+/**
+ * @param array<int> $arr
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureCallingUserlandWithImpureCallbackShuffled(array $arr): array
+{
+	return myMap(arr: $arr, f: static function (int $x): int {
+		echo $x;
+		return $x * 2;
+	});
+}
+
+/**
+ * @param array<int> $arr
+ * @return array<int>
+ * @phpstan-pure
+ */
+function pureCallingMethodWithImpureCallbackByName(Mapper $mapper, array $arr): array
+{
+	return $mapper->map(f: static function (int $x): int {
+		echo $x;
+		return $x * 2;
+	}, arr: $arr);
+}