void|never shouldn't be combined to null but keep void #10759
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@weirdan review & merge please |
| @@ -533,9 +533,9 @@ function bar() { | |||
| }', | |||
| 'output' => '<?php | |||
| /** | |||
| * @return null|string | |||
| * @return string|void | |||
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void in a union looks wrong. Looking at the code here I'd expect null|string actually.
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But actually makes sense here - since it uses implicit return; and not explicit return null; therefore I guess it makes sense, as this clearly distinguishes these 2 cases. E.g. some errors should only report on explicit null but not on void.
I know this isn't possible in native PHP types, but we're in a docblock.
| * this is just one example where psalm uses isVoid and isNever, which is why void|never should not be collapsed to null | ||
| * @param void|never $i |
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This should result in void (as never is the bottom type) and then trigger ReservedWord
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as never is the bottom type
Yes. but when used explictly in docblock never doesn't behave as the bottom type since a long time already on purpose (pretty much only relevant for @return though)
This test is purely to highlight the changes and isn't a feature implemented in this PR, but a bug fix - since currently it this doesn't report an error at all https://psalm.dev/r/bcbea8b9ef
There are various other places that have this bug in psalm and I don't have time to fix them all to implement their checks correctly - that should have happened at the time those were added.
Since psalm internally often checks for isVoid (or isNever) which should include cases of void|never from what I saw, but since the type is changed to null some errors aren't reported.
Initiated by #10742 (review)