Fix phpstan/phpstan#14223: Variable $ in empty() always exists and is not falsy.#5124
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VincentLanglet merged 1 commit intophpstan:2.1.xfrom Mar 3, 2026
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… should not return non-empty-array - ArrayCountValuesDynamicReturnTypeExtension always added NonEmptyArrayType to the result, even when the input array could be empty - Now checks $inputType->isIterableAtLeastOnce() before marking the output as non-empty - Updated existing test assertion for returnsStringOrObjectArray() which returns a possibly-empty array - New regression test in tests/PHPStan/Analyser/nsrt/bug-14223.php
VincentLanglet
approved these changes
Mar 3, 2026
staabm
approved these changes
Mar 3, 2026
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@VincentLanglet please double check the issue-bot results on issue 14107 |
Contributor
Seems ok to me |
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Summary
array_count_values()on a possibly-empty input array was incorrectly returningnon-empty-array<..., int<1, max>>instead ofarray<..., int<1, max>>. This caused a false positiveempty.variableerror when usingempty()on the result, since PHPStan believed the value was always non-falsy.Changes
src/Type/Php/ArrayCountValuesDynamicReturnTypeExtension.phpto check$inputType->isIterableAtLeastOnce()->yes()before addingNonEmptyArrayTypeto the resulttests/PHPStan/Analyser/nsrt/array-count-values.phpfor thereturnsStringOrObjectArray()case which returns a possibly-empty arraytests/PHPStan/Analyser/nsrt/bug-14223.phpRoot cause
ArrayCountValuesDynamicReturnTypeExtensionunconditionally wrapped every output type in anIntersectionTypewithNonEmptyArrayType. This was incorrect because when the input array could be empty (e.g.,list<string>),array_count_values([])returns[]. The fix checks whether the input type is definitely non-empty (isIterableAtLeastOnce()->yes()) before adding theNonEmptyArrayTypeaccessory type.Test
The regression test
tests/PHPStan/Analyser/nsrt/bug-14223.phpverifies:array_count_values()onlist<string>(possibly empty) returnsarray<string, int<1, max>>(notnon-empty-array)array_count_values()onnon-empty-list<string>(definitely non-empty) still returnsnon-empty-array<string, int<1, max>>Fixes phpstan/phpstan#14223