non-empty-string'0' — falsy in PHP — is a perfectly good non-empty-string; that is
what separates it from truthy-string. Analyzers that model the refinement
reject ''; others fall back to plain string and accept it.
References:
- PHPStan TypeNodeResolver non-empty-string resolves to string&AccessoryNonEmptyStringType| 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_non_empty_string.php:48: Argument 1 ($value) is '' of type string but \Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString\acceptsNonEmptyString() takes non-empty-string (no real type) defined at /Users/megurine/repo/php/php-typing-conformance/conformance/tests/phpdoc_advanced_fallback_non_empty_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_non_empty_string.php:48: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString\acceptsNonEmptyString expects non-empty-string, '' given. [identifier=argument.type] [reported-from-level=5] With strict-rulesphpdoc_advanced_fallback_non_empty_string.php:48: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString\acceptsNonEmptyString expects non-empty-string, '' given. [identifier=argument.type]
|
| psalm | 6.16.1Psalm 6.16.1@f1f5de594dc76faf8784e02d3dc4716c91c6f6ac next: 7.0.0-beta19 |
Enforced | phpdoc_advanced_fallback_non_empty_string.php:48: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString\acceptsNonEmptyString expects non-empty-string, but '' provided [InvalidArgument]
|
| mago | 1.46.0mago 1.46.0 | Enforced | phpdoc_advanced_fallback_non_empty_string.php:48: Invalid argument type for argument #1 of `Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString\acceptsNonEmptyString`: expected `non-empty-string`, but found `string('')`. [invalid-argument]
|
| mir | 0.70.1mir 0.70.1 | Enforced | phpdoc_advanced_fallback_non_empty_string.php:48: InvalidArgument: Argument $value of acceptsNonEmptyString() expects 'non-empty-string', got '""' [MIR0201]
|
| phpantom | 0.9.0phpantom_lsp 0.9.0 | Enforced | phpdoc_advanced_fallback_non_empty_string.php:48: Argument 1 ($value) expects non-empty-string, got '' [type_mismatch_argument]
|
| intelephense | 1.18.5intelephense 1.18.5 | Not enforced | 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 | Not enforced | No diagnostics reported.
|
| steins | 0.1.5steins 0.1.5 (2026-08-12 revision 39b4cc1) | Enforced | phpdoc_advanced_fallback_non_empty_string.php:48: argument "" to acceptsNonEmptyString() violates declared @param non-empty-string $value — declared contract violation [phpdoc.param-mismatch]
|
| phpstan-strict | 2.2.8PHPStan - PHP Static Analysis Tool 2.2.8 | Enforced | phpdoc_advanced_fallback_non_empty_string.php:48: Parameter #1 $value of function Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString\acceptsNonEmptyString expects non-empty-string, '' given. [identifier=argument.type]
|
| psalm-next | 7.0.0-beta19Psalm 7.0.0-beta19@7e751c06a756fa64dc4c759c09fe4a173afcb433 | Enforced | phpdoc_advanced_fallback_non_empty_string.php:48: Argument 1 of Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString\acceptsNonEmptyString expects non-empty-string, but '' provided [InvalidArgument]
|
<?php
declare(strict_types=1);
namespace Conformance\Tests\PhpdocAdvancedFallbackNonEmptyString;
/**
* `non-empty-string`
*
* A string of length at least one. It is a length constraint, not a truthiness
* one, so `'0'` — falsy in PHP — is a perfectly good `non-empty-string`; that is
* what separates it from `truthy-string`. Analyzers that model the refinement
* reject `''`; others fall back to plain `string` and accept it.
*
* References:
* - PHPStan TypeNodeResolver `non-empty-string` resolves to string&AccessoryNonEmptyStringType
*/
/**
* @return non-empty-string
*/
function returnsNonEmptyString() // T: non-empty-string
{
return 'x'; // V
}
function acceptsString(string $value): void
{
}
/**
* @param non-empty-string $value
*/
function acceptsNonEmptyString($value): void // T: non-empty-string
{
}
// A `non-empty-string` value always satisfies a native `string` parameter.
acceptsString(returnsNonEmptyString()); // V
// Any string with at least one character satisfies the parameter — `'0'`
// included, however falsy it is.
acceptsNonEmptyString('x'); // V
acceptsNonEmptyString('0'); // V
// The empty string: enforcing analyzers reject it, others fall back to `string`
// and accept it.
acceptsNonEmptyString(''); // E?: '' is not a non-empty-string