Fix phpstan/phpstan#11351: Defining Array Constants in PHP Traits Causes Errors When Using Class Constants as Keys or Values#5115
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staabm merged 4 commits intophpstan:2.1.xfrom Mar 1, 2026
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VincentLanglet
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Mar 1, 2026
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will also fix phpstan/phpstan#11088 |
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@phpstan-bot add a regression test for phpstan/phpstan#11088 |
- Fixed ConflictingTraitConstantsRule to resolve trait constant value expressions in the context of the using class, not the trait itself - When a trait constant uses self::CONST, it should resolve against the using class since that's how PHP evaluates trait constants at runtime - New regression test in tests/PHPStan/Rules/Traits/data/bug-11351.php
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Summary
When a trait defines an array constant that uses
self::to reference class constants (as keys or values), PHPStan falsely reported that the class overrides the trait constant with a different value. This happened because the trait constant expression was resolved in the trait's own context, whereself::couldn't see the using class's constants.Changes
src/Rules/Traits/ConflictingTraitConstantsRule.phpto resolve the trait constant value expression usingInitializerExprContext::fromClassReflection($classReflection)(the using class) instead ofInitializerExprContext::fromClass()with the trait's own nametests/PHPStan/Rules/Traits/data/bug-11351.phpwith three scenarios:self::used as array key, as array value, and as both key and valuetestBug11351()intests/PHPStan/Rules/Traits/ConflictingTraitConstantsRuleTest.phpRoot cause
In
ConflictingTraitConstantsRule, the trait constant's value expression was resolved usingInitializerExprContext::fromClass()with the trait's declaring class name. This meant thatself::CAin the trait was resolved against the trait itself, which doesn't defineCA. The class constant's value, however, was correctly resolved against the using class. This caused a type mismatch (e.g.,non-empty-array<int|string, 'CA'>vsarray{abc: 'CA'}), triggering a false positive.The fix resolves both the class and trait constant values in the context of the using class, which matches PHP's runtime behavior where
self::in a trait refers to the class using the trait.Test
Added
tests/PHPStan/Rules/Traits/data/bug-11351.phpwith three test cases:self::as array keyself::as array valueself::as both key and valueAll expect no errors (the false positives should be gone).
Fixes phpstan/phpstan#11351
Closes phpstan/phpstan#11088