class-stringclass-string is a refinement of string, so a @return class-string
value always satisfies a native string parameter — analyzers that do not
model it still fall back to string. Analyzers that enforce the refinement
additionally reject a literal that is not a known class name.
References:
- PHPStan TypeNodeResolver class-string resolves to ClassStringType| Analyzer | Version | Result | Diagnostics |
|---|---|---|---|
| phan | 6.0.7Phan 6.0.7 php-ast version 1.1.3 PHP version used to run Phan: 8.5.9 | Enforced | phpdoc_advanced_fallback_class_string.php:46: Possible use of a classlike '\not a class name' with an invalid FQSEN. [PhanInvalidFQSENInClasslike] phpdoc_advanced_fallback_class_string.php:46: Argument 1 ($value) is 'not a class name' of type string but \Conformance\Tests\PhpdocAdvancedFallbackClassString\acceptsClassString() takes class-string (no real type) defined at /Users/megurine/repo/php/php-typing-conformance/conformance/tests/phpdoc_advanced_fallback_class_string.php:34 (the inferred real argument type has nothing in common with the parameter's phpdoc type) [PhanTypeMismatchArgumentProbablyReal]
|
| phpstan | 2.2.8PHPStan - PHP Static Analysis Tool 2.2.8 | Enforced reported Lv.5+ | phpdoc_advanced_fallback_class_string.php:46: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackClassString\acceptsClassString expects class-string, string given. [identifier=argument.type] [reported-from-level=5] With strict-rulesphpdoc_advanced_fallback_class_string.php:46: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackClassString\acceptsClassString expects class-string, string given. [identifier=argument.type]
|
| psalm | 6.16.1Psalm 6.16.1@f1f5de594dc76faf8784e02d3dc4716c91c6f6ac next: 7.0.0-beta19 |
Enforced | phpdoc_advanced_fallback_class_string.php:46: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackClassString\acceptsClassString expects class-string, but parent type 'not a class name' provided [ArgumentTypeCoercion] phpdoc_advanced_fallback_class_string.php:46: Class, interface or enum named not a class name does not exist [UndefinedClass]
|
| mago | 1.46.0mago 1.46.0 | Widened to string | No diagnostics reported.
|
| mir | 0.70.1mir 0.70.1 | Widened to string | No diagnostics reported.
|
| phpantom | 0.9.0phpantom_lsp 0.9.0 | Not enforced | No diagnostics reported.
|
| intelephense | 1.18.5intelephense 1.18.5 | Widened to string | No diagnostics reported.
|
| phpy | 0.2.0phpy 0.2.0 | Not enforced | No diagnostics reported.
|
| qodana | 262.8665.325Qodana 262.8665.325 | Not enforced | No diagnostics reported.
|
| noverify | 0.5.5NoVerify, version 0.5.5: built on: 2025.04.22 14:36:46 OS: r-kuchinskas arm64 Commit: 4774b82f8adc53fbef38f95e97af4b953b4d1529 | Widened to string | No diagnostics reported.
|
| steins | 0.1.5steins 0.1.5 (2026-08-12 revision 39b4cc1) | Widened to string | No diagnostics reported.
Notes: `class-string` lowers to `ContractTy::StrOpaque` (ADR-0038: non-extensional membership) rather than checking the string names a declared class, so it accepts any string and rejects only non-strings — the same acceptance a bare `string` parameter gives. |
| phpstan-strict | 2.2.8PHPStan - PHP Static Analysis Tool 2.2.8 | Enforced | phpdoc_advanced_fallback_class_string.php:46: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackClassString\acceptsClassString expects class-string, string given. [identifier=argument.type]
|
| psalm-next | 7.0.0-beta19Psalm 7.0.0-beta19@7e751c06a756fa64dc4c759c09fe4a173afcb433 | Enforced | phpdoc_advanced_fallback_class_string.php:46: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackClassString\acceptsClassString expects class-string, but parent type 'not a class name' provided [ArgumentTypeCoercion] phpdoc_advanced_fallback_class_string.php:46: Class, interface or enum named not a class name does not exist [UndefinedClass]
|
<?php
declare(strict_types=1);
namespace Conformance\Tests\PhpdocAdvancedFallbackClassString;
/**
* `class-string`
*
* `class-string` is a refinement of `string`, so a `@return class-string`
* value always satisfies a native `string` parameter — analyzers that do not
* model it still fall back to `string`. Analyzers that enforce the refinement
* additionally reject a literal that is not a known class name.
*
* References:
* - PHPStan TypeNodeResolver `class-string` resolves to ClassStringType
*/
/**
* @return class-string
*/
function returnsClassString() // T: class-string
{
return \stdClass::class; // V
}
function acceptsString(string $value): void
{
}
/**
* @param class-string $value
*/
function acceptsClassString($value): void // T: class-string
{
}
// A `class-string` value always satisfies a native `string` parameter.
acceptsString(returnsClassString()); // V
// A real class name satisfies the refined parameter.
acceptsClassString(\stdClass::class); // V
// A non-class literal string: enforcing analyzers reject it, others fall back
// to `string` and accept it.
acceptsClassString('not a class name'); // E?: non-class-string should be rejected where class-string is required