Support named arguments after unpacking

Author: herndlm

src/Php/PhpVersions.php

@@ -38,4 +38,9 @@ public function supportsNamedArguments(): TrinaryLogic
 		return IntegerRangeType::fromInterval(80000, null)->isSuperTypeOf($this->phpVersions)->result;
 	}
 
+	public function supportsNamedArgumentAfterUnpackedArgument(): TrinaryLogic
+	{
+		return IntegerRangeType::fromInterval(80100, null)->isSuperTypeOf($this->phpVersions)->result;
+	}
+
 }

src/Rules/FunctionCallParametersCheck.php

@@ -27,6 +27,7 @@
 use PHPStan\Type\VerbosityLevel;
 use function array_fill;
 use function array_key_exists;
+use function array_slice;
 use function count;
 use function implode;
 use function in_array;
@@ -81,12 +82,15 @@ public function check(
 	{
 		$functionParametersMinCount = 0;
 		$functionParametersMaxCount = 0;
+		$functionParameterNames = [];
 		foreach ($parametersAcceptor->getParameters() as $parameter) {
 			if (!$parameter->isOptional()) {
 				$functionParametersMinCount++;
 			}
 
 			$functionParametersMaxCount++;
+
+			$functionParameterNames[] = $parameter->getName();
 		}
 
 		if ($parametersAcceptor->isVariadic()) {
@@ -101,6 +105,12 @@ public function check(
 		$hasUnpackedArgument = false;
 		$errors = [];
 		foreach ($args as $arg) {
+			$argumentName = null;
+			if ($arg->name !== null) {
+				$hasNamedArguments = true;
+				$argumentName = $arg->name->toString();
+			}
+
 			if ($hasNamedArguments && $arg->unpack) {
 				$errors[] = RuleErrorBuilder::message('Named argument cannot be followed by an unpacked (...) argument.')
 					->identifier('argument.unpackAfterNamed')
@@ -109,20 +119,25 @@ public function check(
 					->build();
 			}
 			if ($hasUnpackedArgument && !$arg->unpack) {
-				$errors[] = RuleErrorBuilder::message('Unpacked argument (...) cannot be followed by a non-unpacked argument.')
-					->identifier('argument.nonUnpackAfterUnpacked')
-					->line($arg->getStartLine())
-					->nonIgnorable()
-					->build();
+				if ($argumentName !== null && $scope->getPhpVersion()->supportsNamedArgumentAfterUnpackedArgument()->yes()) {
+					if (in_array($argumentName, array_slice($functionParameterNames, 0, count($arguments)), true)) {
+						$errors[] = RuleErrorBuilder::message(sprintf('Named parameter cannot overwrite already unpacked argument $%s.', $argumentName))
+							->identifier('argument.namedOverwriteAfterUnpacked')
+							->line($arg->getStartLine())
+							->nonIgnorable()
+							->build();
+					}
+				} else {
+					$errors[] = RuleErrorBuilder::message('Unpacked argument (...) cannot be followed by a non-unpacked argument.')
+						->identifier('argument.nonUnpackAfterUnpacked')
+						->line($arg->getStartLine())
+						->nonIgnorable()
+						->build();
+				}
 			}
 			if ($arg->unpack) {
 				$hasUnpackedArgument = true;
 			}
-			$argumentName = null;
-			if ($arg->name !== null) {
-				$hasNamedArguments = true;
-				$argumentName = $arg->name->toString();
-			}
 			if ($arg->unpack) {
 				$type = $scope->getType($arg->value);
 				$arrays = $type->getConstantArrays();

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -499,6 +499,24 @@ public function testNamedArguments(): void
 		$this->analyse([__DIR__ . '/data/named-arguments.php'], $errors);
 	}
 
+	public function testNamedArgumentsAfterUnpacking(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('Test requires PHP 8.1.');
+		}
+
+		$this->analyse([__DIR__ . '/data/named-arguments-after-unpacking.php'], [
+			[
+				'Named parameter cannot overwrite already unpacked argument $b.',
+				14,
+			],
+			[
+				'Argument for parameter $b has already been passed.',
+				14,
+			],
+		]);
+	}
+
 	public function testBug4514(): void
 	{
 		$this->analyse([__DIR__ . '/data/bug-4514.php'], []);
@@ -1936,4 +1954,13 @@ public function testBug12051(): void
 		$this->analyse([__DIR__ . '/data/bug-12051.php'], []);
 	}
 
+	public function testBug11418(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('Test requires PHP 8.1.');
+		}
+
+		$this->analyse([__DIR__ . '/data/bug-11418.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Functions/data/bug-11418.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Bug11418;
+
+function foo(int $a, int $b, int $c = 3, int $d = 4): int {
+	return $a + $b + $c + $d;
+}
+
+var_dump(foo(...[1, 2], d: 40)); // 46

tests/PHPStan/Rules/Functions/data/named-arguments-after-unpacking.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace FunctionNamedArgumentsAfterUnpacking;
+
+// https://www.php.net/manual/en/functions.arguments.php#example-180
+
+function foo($a, $b, $c = 3, $d = 4) {
+	return $a + $b + $c + $d;
+}
+
+var_dump(foo(...[1, 2], d: 40)); // 46
+var_dump(foo(...['b' => 2, 'a' => 1], d: 40)); // 46
+
+var_dump(foo(...[1, 2], b: 20)); // Fatal error. Named parameter $b overwrites previous argument