Fix phpstan/phpstan#14019: Assignment in a key of array destructuring is ignored#5164
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staabm merged 2 commits intophpstan:2.1.xfrom Mar 9, 2026
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- Propagate scope from key expression processing in list/array destructuring - Previously the scope result from processing key expressions was discarded, so assignments like `[($a = 'foo') => $b] = [...]` left `$a` undefined - New regression test in tests/PHPStan/Analyser/nsrt/bug-14019.php Closes phpstan/phpstan#14019
staabm
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Mar 9, 2026
| $throwPoints = array_merge($throwPoints, $keyResult->getThrowPoints()); | ||
| $impurePoints = array_merge($impurePoints, $keyResult->getImpurePoints()); | ||
| $isAlwaysTerminating = $isAlwaysTerminating || $keyResult->isAlwaysTerminating(); | ||
| // no need for $keyResult->getScope() |
staabm
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Mar 9, 2026
VincentLanglet
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Mar 9, 2026
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Summary
When using an assignment expression as a key in array destructuring (e.g.,
[($a = 'foo') => $b] = ['foo' => 1]), PHPStan incorrectly reported$aas possibly undefined with typemixed. The variable should be recognized as assigned with its correct type.Changes
src/Analyser/ExprHandler/AssignHandler.phpto propagate the scope returned from processing key expressions in array destructuringtests/PHPStan/Analyser/nsrt/bug-14019.phpRoot cause
In
AssignHandler.php, when processing array destructuring (list()/[]), the code correctly calledprocessExprNode()on key expressions to collect side effects (yield, throw points, impure points), but explicitly discarded the resulting scope with the comment// no need for $keyResult->getScope(). This meant any assignments within key expressions (like$a = 'foo') were not reflected in the scope, causing the assigned variable to appear undefined.The fix replaces the discarded scope with
$scope = $keyResult->getScope()so that assignments in key expressions are properly tracked.Test
Added
tests/PHPStan/Analyser/nsrt/bug-14019.phpwhich verifies that$agets type'foo'and$bgets type1after[($a = 'foo') => $b] = ['foo' => 1].Fixes phpstan/phpstan#14019