[GromNaN]

getNativeType() is documented as returning only what PHP's native type system knows, ignoring PHPDoc. The native type of a variadic parameter does not follow that rule: it uses acceptsNamedArguments(), which comes from the @no-named-arguments PHPDoc tag.

As a result, with treatPhpDocTypesAsCertain: false, PHPStan still reports an @phpstan-assert on such a parameter as redundant, even though the report relies on PHPDoc:

/**
 * @template TItem
 * @param TItem[] $parameter
 * @phpstan-assert list<TItem> $parameter
 */
private static function validateVariadicParameter(array $parameter): void {}

/**
 * @no-named-arguments
 */
public function groupBy(string ...$groupBy): void
{
    self::validateVariadicParameter($groupBy); // reported even with treatPhpDocTypesAsCertain: false
}

The native parameter type now keeps string keys whenever the PHP version supports named arguments, and only the PHPDoc-aware type uses acceptsNamedArguments(). With treatPhpDocTypesAsCertain: false, $groupBy is array<int<0, max>|string, string> for the analyser, the assertion narrows, and nothing is reported. With the default true, the PHPDoc-aware type is still list<string> and the call is reported as before.

The native mirror in turbo-ext/src/MutatingScope.cpp applies the same change. tests/PHPStan/Analyser/nsrt/no-named-arguments.php now expects array<int<0, max>|string, float> from assertNativeType, and a rule test covers the treatPhpDocTypesAsCertain: false case.

The other half of the @phpstan-assert behaviour, method templates resolved to their bound, is in #6823.

[phpstan-bot]

This pull request has been marked as ready for review.