lowercase-stringstrtolower(). That is a weaker claim than "made of
lowercase letters": a string with no cased characters at all, '123' or '',
qualifies. A single uppercase character anywhere disqualifies the whole
string. Analyzers that model the refinement reject such a literal; others
fall back to plain string and accept it.
References:
- PHPStan TypeNodeResolver lowercase-string resolves to string&AccessoryLowercaseStringType| 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 | Not enforced | No diagnostics reported.
|
| phpstan | 2.2.15PHPStan - PHP Static Analysis Tool 2.2.15 | Enforced reported Lv.5+ | phpdoc_advanced_fallback_lowercase_string.php:49: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, 'ABC' given. [reported-from-level=5] phpdoc_advanced_fallback_lowercase_string.php:52: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, 'abC' given. [reported-from-level=5] With strict-rulesphpdoc_advanced_fallback_lowercase_string.php:49: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, 'ABC' given. phpdoc_advanced_fallback_lowercase_string.php:52: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, 'abC' given.
|
| psalm | 6.18.0Psalm 6.18.0@536dd6236b39a5115385b0307b42d6d1ad431a02 next: 7.0.0-beta22 |
Enforced | phpdoc_advanced_fallback_lowercase_string.php:49: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, but 'ABC' provided [InvalidArgument] phpdoc_advanced_fallback_lowercase_string.php:52: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, but 'abC' provided [InvalidArgument]
|
| mago | 1.50.0mago 1.50.0 | Enforced | phpdoc_advanced_fallback_lowercase_string.php:49: Invalid argument type for argument #1 of `Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString`: expected `lowercase-string`, but found `string('ABC')`. [invalid-argument]
phpdoc_advanced_fallback_lowercase_string.php:52: Invalid argument type for argument #1 of `Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString`: expected `lowercase-string`, but found `string('abC')`. [invalid-argument]
|
| mir | 0.78.0mir 0.78.0 | Widened to string | No diagnostics reported.
|
| phpantom | 0.10.0phpantom_lsp 0.10.0 | Enforced | phpdoc_advanced_fallback_lowercase_string.php:49: Argument 1 ($value) expects lowercase-string, got 'ABC' [type_mismatch_argument] phpdoc_advanced_fallback_lowercase_string.php:52: Argument 1 ($value) expects lowercase-string, got 'abC' [type_mismatch_argument]
|
| intelephense | 1.18.5intelephense 1.18.5 | Widened to string | No diagnostics reported.
|
| phpactor | 2026.06.23.0Phpactor 2026.06.23.0 | Not enforced | No diagnostics reported.
|
| phpy | 1.0.19274phpy 1.0.19274 | Not enforced | No diagnostics reported.
|
| qodana | 262.9437.196Qodana 262.9437.196 | 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 | Not enforced | No diagnostics reported.
|
| steins | 0.1.8steins 0.1.8 (2026-09-21 revision 76306a9) | Enforced | phpdoc_advanced_fallback_lowercase_string.php:49: argument "ABC" to acceptsLowercaseString() violates declared @param lowercase-string $value — declared contract violation [phpdoc.param-mismatch] phpdoc_advanced_fallback_lowercase_string.php:52: argument "abC" to acceptsLowercaseString() violates declared @param lowercase-string $value — declared contract violation [phpdoc.param-mismatch]
|
| phpstan-strict | 2.2.15PHPStan - PHP Static Analysis Tool 2.2.15 | Enforced | phpdoc_advanced_fallback_lowercase_string.php:49: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, 'ABC' given. phpdoc_advanced_fallback_lowercase_string.php:52: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, 'abC' given.
|
| psalm-next | 7.0.0-beta22Psalm 7.0.0-beta22@de27e5724ee5997a1e3baee4d394ca6f4e46eba0 | Enforced | phpdoc_advanced_fallback_lowercase_string.php:49: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, but 'ABC' provided [InvalidArgument] phpdoc_advanced_fallback_lowercase_string.php:52: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackLowercaseString\acceptsLowercaseString expects lowercase-string, but 'abC' provided [InvalidArgument]
|
<?php
declare(strict_types=1);
namespace Conformance\Tests\PhpdocAdvancedFallbackLowercaseString;
/**
* `lowercase-string`
*
* A string unchanged by `strtolower()`. That is a weaker claim than "made of
* lowercase letters": a string with no cased characters at all, `'123'` or `''`,
* qualifies. A single uppercase character anywhere disqualifies the whole
* string. Analyzers that model the refinement reject such a literal; others
* fall back to plain `string` and accept it.
*
* References:
* - PHPStan TypeNodeResolver `lowercase-string` resolves to string&AccessoryLowercaseStringType
*/
/**
* @return lowercase-string
*/
function returnsLowercaseString() // T: lowercase-string
{
return 'abc'; // V
}
function acceptsString(string $value): void
{
}
/**
* @param lowercase-string $value
*/
function acceptsLowercaseString($value): void // T: lowercase-string
{
}
// A `lowercase-string` value always satisfies a native `string` parameter.
acceptsString(returnsLowercaseString()); // V
// Lowercase letters satisfy the parameter, and so does a string with nothing
// to lowercase.
acceptsLowercaseString('abc'); // V
acceptsLowercaseString('123'); // V
acceptsLowercaseString(''); // V
// A fully uppercase literal is outside the refinement.
acceptsLowercaseString('ABC'); // E?: 'ABC' is not a lowercase-string
// So is a mixed one, on the strength of a single character.
acceptsLowercaseString('abC'); // E?: 'abC' is not a lowercase-string