CallableTypeHelper - copy variadic parameters if the accepting closure has more parameters

Author: ondrejmirtes

src/Type/CallableTypeHelper.php

@@ -4,7 +4,9 @@
 
 use PHPStan\Reflection\ParametersAcceptor;
 use PHPStan\TrinaryLogic;
+use function array_key_exists;
 use function array_merge;
+use function count;
 use function sprintf;
 
 class CallableTypeHelper
@@ -19,6 +21,23 @@ public static function isParametersAcceptorSuperTypeOf(
 		$theirParameters = $theirs->getParameters();
 		$ourParameters = $ours->getParameters();
 
+		$lastParameter = null;
+		foreach ($theirParameters as $theirParameter) {
+			$lastParameter = $theirParameter;
+		}
+		if (
+			$lastParameter !== null
+			&& $lastParameter->isVariadic()
+			&& count($theirParameters) < count($ourParameters)
+		) {
+			foreach ($ourParameters as $i => $ourParameter) {
+				if (array_key_exists($i, $theirParameters)) {
+					continue;
+				}
+				$theirParameters[] = $lastParameter;
+			}
+		}
+
 		$result = null;
 		foreach ($theirParameters as $i => $theirParameter) {
 			$parameterDescription = $theirParameter->getName() === '' ? sprintf('#%d', $i + 1) : sprintf('#%d $%s', $i + 1, $theirParameter->getName());

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -1421,4 +1421,18 @@ public function testBug6175(): void
 		$this->analyse([__DIR__ . '/data/bug-6175.php'], []);
 	}
 
+	public function testBug9699(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('Test requires PHP 8.1');
+		}
+
+		$this->analyse([__DIR__ . '/data/bug-9699.php'], [
+			[
+				'Parameter #1 $f of function Bug9699\int_int_int_string expects Closure(int, int, int, string): int, Closure(int, int, int ...): int given.',
+				19,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Functions/data/bug-9699.php

@@ -0,0 +1,19 @@
+<?php // lint >= 8.1
+
+namespace Bug9699;
+
+function withVariadicParam(int $a, int $b, int ...$rest): int
+{
+	return array_sum([$a, $b, ...$rest]);
+}
+
+/**
+ * @param \Closure(int, int, int, string): int $f
+ */
+function int_int_int_string(\Closure $f): void
+{
+	$f(0, 0, 0, '');
+}
+
+// false negative: expected issue here
+int_int_int_string(withVariadicParam(...));