Wrong return type in ternary operator

[EgorBurykin]

Bug report

Stan seems can not derive correct type if ternary operator used like this:
$test->test() ? $test->test()->format('d') : null

Code snippet that reproduces the problem

https://phpstan.org/r/ff44c8c8-06ca-470a-a716-ebd334aee215

Expected output

Stan should not complain about type.

[ondrejmirtes]

Are you sure? :D https://3v4l.org/jNRDj

[ondrejmirtes]

I mean, your example shows exactly why this error is reported.

[EgorBurykin]

I modified example to show why it is bad. https://phpstan.org/r/37170718-c033-437e-bbe0-2e9524ea6875

[ondrejmirtes]

And what error do you expect? The original post states:

Expected output

Stan should not complain about type.

[pepakriz]

I expect this because of every $test->test() call can return different result type.

+---------------------------------------------------------------+
| Line | test.php                                               |
+---------------------------------------------------------------+
| 17   | Cannot call method format() on DateTimeImmutable|null. |
+---------------------------------------------------------------+

I know that phpstan has some kind of black magic which uses caching for return types but I don't like it.

[ondrejmirtes]

Yeah, I plan to do something about it, stay tuned.

[teohhanhui]

Is this the same issue?

https://phpstan.org/r/4911db47-3f00-4340-b211-6d1e85f64db2

[ondrejmirtes]

@teohhanhui What output do you expect?

[teohhanhui]

phpstan should be able to tell that json_decode might not return an object, and so the assignment should raise an error for incompatible types.

[ondrejmirtes]

json_decode return type is mixed so it can return anything, but it also might return the correct thing. That's why it doesn't complain. And it's unrelated to this issue.

[teohhanhui]

But we know which types json_decode can return, right? It's only the types that are possible in JSON.

Something like:

Property MatchesJsonSchema::$schema (object) does not accept object|array|string|int|float|bool|null.

[ondrejmirtes]

Yeah but it would be too annoying to have them listed, because when you know that your JSON string contains an object, it would be too annoying to check for the other types.

[teohhanhui]

Isn't that where inline phpdocs come in to save the day? We already have to do the same in many places. If we "know" something, we have to give the correct hints to the static analyzer.

For example:

https://phpstan.org/r/526680b3-006f-466c-b005-f5ab44f1156a
https://3v4l.org/bMtP1

[ondrejmirtes]

Yes, you can use them. Or assert().

[ondrejmirtes]

But it would be annoying to users to require it.

[ondrejmirtes]

And PHPStan checks in that case work: https://phpstan.org/r/126f39f4-6143-43a7-8eb7-b44728d54b25

[ondrejmirtes]

But please stop discussing this in this issue, it's unrelated.

[phpstan-bot]

@EgorBurykin PHPStan now reports different result with your code snippet:

@@ @@
-17: Cannot call method format() on DateTimeImmutable|null.
+No errors

[phpstan-bot]

@teohhanhui PHPStan now reports different result with your code snippet:

@@ @@
-No errors
+13: Method MatchesJsonSchema::__construct() has parameter $schema with no value type specified in iterable type array.

Full report

Line	Error
13	Method MatchesJsonSchema::__construct() has parameter $schema with no value type specified in iterable type array.

[phpstan-bot]

@ondrejmirtes PHPStan now reports different result with your code snippet:

@@ @@
+13: Method MatchesJsonSchema::__construct() has parameter $schema with no value type specified in iterable type array.
+17: PHPDoc tag @var for variable $array has no value type specified in iterable type array.
 18: Property MatchesJsonSchema::$schema (object) does not accept array.

Full report

Line	Error
13	Method MatchesJsonSchema::__construct() has parameter $schema with no value type specified in iterable type array.
17	PHPDoc tag @var for variable $array has no value type specified in iterable type array.
18	Property MatchesJsonSchema::$schema (object) does not accept array.

[ondrejmirtes]

Fixed: phpstan/phpstan-src@d4edc59

[github-actions]

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