Fix phpstan/phpstan#14311: nullsafe.neverNull false positive: nullsafe on variable assigned from array<K, V> with ??, isset(), or array_key_exists()#5247
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…ect can be null - In IssetCheck, the nullsafe.neverNull error was reported unconditionally for NullsafePropertyFetch inside ??, isset(), and empty(), without checking if the left side of ?-> could actually be null - Added a check on $expr->var's type before reporting the error, consistent with how NullsafePropertyFetchRule already handles this - Updated test expectations for bug-7109 in NullCoalesceRuleTest, IssetRuleTest, and EmptyRuleTest to remove false positive expectations - New regression test in tests/PHPStan/Rules/Variables/data/bug-14311.php
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Summary
When using
?->on a variable that could be null (e.g.,$bar = $stations[$key] ?? null; $bar?->address ?? 'Unknown'), PHPStan incorrectly reportednullsafe.neverNull— "Using nullsafe property access is unnecessary. Use -> instead." This happened with??,isset(), andempty()contexts.Changes
$expr->var's type insrc/Rules/IssetCheck.phpbefore reportingnullsafe.neverNull, matching the logic already used inNullsafePropertyFetchRuletests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php— removed 3 false positive expectations from bug-7109 testtests/PHPStan/Rules/Variables/IssetRuleTest.php— removed 3 false positive expectations from bug-7109 testtests/PHPStan/Rules/Variables/EmptyRuleTest.php— removed 4 false positive expectations from bug-7109 testtests/PHPStan/Rules/Variables/data/bug-14311.phpcovering all three variants (??,isset(),array_key_exists())Root cause
In
IssetCheck::check(), when the expression passed to??/isset()/empty()was aNullsafePropertyFetch, the code unconditionally reported the nullsafe as unnecessary without checking whether the left side of?->could actually be null. The standaloneNullsafePropertyFetchRulealready had this check ($calledOnType->isNull()->no()), butIssetCheckwas missing it. This gave contradictory advice — PHPStan would tell users to replace?->with->, but then would report an error about accessing a property on a nullable type.Test
Added
tests/PHPStan/Rules/Variables/data/bug-14311.phpwith three functions testing??,isset(), andarray_key_exists()variants. Each function creates aStation|nullvariable and uses?->address ?? 'Unknown'. The test expects no errors.Fixes phpstan/phpstan#14311