LeftTrait::$prop is string and RightTrait::$prop is int. Composing both into one
class is a compile-time fatal error in PHP ("traits define the same property … the
definition differs and is considered incompatible"). Analyzers diverge on whether they
report this statically. PHPStan is silent even though the program cannot run.
Source lead: Mago analyzer test trait_property_type_conflicts.| 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 | Pass | regressions_trait_property_type_conflict.php:20: Declaration of \Conformance\Tests\RegressionsTraitPropertyTypeConflict\Composed::prop of real type string is incompatible with inherited property \Conformance\Tests\RegressionsTraitPropertyTypeConflict\RightTrait::prop of real type int defined at /Users/megurine/repo/php/php-typing-conformance/conformance/tests/regressions_trait_property_type_conflict.php:25 [PhanIncompatibleRealPropertyType] |
| phpstan | 2.2.8PHPStan - PHP Static Analysis Tool 2.2.8 | Pass | No diagnostics reported. |
| psalm | 6.16.1Psalm 6.16.1@f1f5de594dc76faf8784e02d3dc4716c91c6f6ac next: 7.0.0-beta19 |
Pass (pzoom≠) | regressions_trait_property_type_conflict.php:20: Conformance\Tests\RegressionsTraitPropertyTypeConflict\Composed has an uninitialized property Conformance\Tests\RegressionsTraitPropertyTypeConflict\LeftTrait::$prop, but no constructor [MissingConstructor] pzoom (Psalm port)regressions_trait_property_type_conflict.php:28: Conformance\Tests\RegressionsTraitPropertyTypeConflict\Composed has an uninitialized property Conformance\Tests\RegressionsTraitPropertyTypeConflict\Composed::$prop, but no constructor [MissingConstructor] |
| mago | 1.46.0mago 1.46.0 | Pass | regressions_trait_property_type_conflict.php:31: Property `$prop` is defined differently in `Conformance\Tests\RegressionsTraitPropertyTypeConflict\LeftTrait` and `Conformance\Tests\RegressionsTraitPropertyTypeConflict\RightTrait` used by `conformance\tests\regressionstraitpropertytypeconflict\composed`: type declaration differs (TUnion { types: [Scalar(String(TString { literal: None, is_numeric: false, is_truthy: false, is_non_empty: false, is_callable: false, casing: Unspecified }))], flags: UnionFlags(0) } vs TUnion { types: [Scalar(Integer(Unspecified))], flags: UnionFlags(0) }) [incompatible-property-type] |
| mir | 0.70.1mir 0.70.1 | Pass | No diagnostics reported. |
| phpantom | 0.9.0phpantom_lsp 0.9.0 | Pass | No diagnostics reported. |
| intelephense | 1.18.5intelephense 1.18.5 | Pass | No diagnostics reported. |
| phpy | 0.2.0phpy 0.2.0 | Pass | No diagnostics reported. |
| qodana | 262.8665.325Qodana 262.8665.325 | Pass | No diagnostics reported. |
| noverify | 0.5.5NoVerify, version 0.5.5: built on: 2025.04.22 14:36:46 OS: r-kuchinskas arm64 Commit: 4774b82f8adc53fbef38f95e97af4b953b4d1529 | Pass | No diagnostics reported. |
| steins | 0.1.5steins 0.1.5 (2026-08-12 revision 39b4cc1) | Pass | No diagnostics reported. |
| phpstan-strict | 2.2.8PHPStan - PHP Static Analysis Tool 2.2.8 | Pass | No diagnostics reported. |
| psalm-next | 7.0.0-beta19Psalm 7.0.0-beta19@7e751c06a756fa64dc4c759c09fe4a173afcb433 | Pass | regressions_trait_property_type_conflict.php:20: Conformance\Tests\RegressionsTraitPropertyTypeConflict\Composed has an uninitialized property Conformance\Tests\RegressionsTraitPropertyTypeConflict\LeftTrait::$prop, but no constructor [MissingConstructor] |
<?php
declare(strict_types=1);
namespace Conformance\Tests\RegressionsTraitPropertyTypeConflict;
/**
* Conflicting property types composed from two traits.
*
* `LeftTrait::$prop` is `string` and `RightTrait::$prop` is `int`. Composing both into one
* class is a compile-time fatal error in PHP ("traits define the same property … the
* definition differs and is considered incompatible"). Analyzers diverge on whether they
* report this statically. PHPStan is silent even though the program cannot run.
*
* Source lead: Mago analyzer test `trait_property_type_conflicts`.
*/
trait LeftTrait
{
public string $prop; // E<psalm>: reports only MissingConstructor for the uninitialized $prop, not the type conflict // E<phan>: PhanIncompatibleRealPropertyType — detects the string-vs-int conflict
}
trait RightTrait
{
public int $prop;
}
final class Composed
{
use LeftTrait;
use RightTrait; // E<mago>: incompatible-property-type — detects the conflict. PHPStan is silent on both the conflict and the missing constructor, even though PHP fatals at compile time
}