Accessing different nested object properties trigger MixedPropertyFetch

[annuh]

Hi,

I've noticed an issue when accessing multiple nested object properties.

Hopefully this snippet explains the issue:

<?php
/**
 * @var object{
 *     Nested: object{
 *         foo: string,
 *         bar: string,
 *    }
 * } $object
 */
if ($object->Nested->foo !== 'Foo') {
    return null;
}
if ($object->Nested->bar !== 'Bar') { // the MixedPropertyFetch is unexpected here
    return null;
}

Link to the snippet https://psalm.dev/r/4ec39c5d44

FYI this only happens with nested objects, accessing multiple properties directly on $response works as expected.

[psalm-github-bot[bot]]

I found these snippets:

https://psalm.dev/r/4ec39c5d44

<?php
/**
 * @var object{
 *     Nested: object{
 *         foo: string,
 *         bar: string,
 *    }
 * } $object
 */
if ($object->Nested->foo !== 'Foo') {
    return null;
}
if ($object->Nested->bar !== 'Bar') {
    return null;
}

Psalm output (using commit 5095f4e):

INFO: MixedPropertyFetch - 13:5 - Cannot fetch property on mixed var $object->Nested

[theodorejb]

I ran into a similar issue with nested objects when throwing an exception: https://psalm.dev/r/f7ffc1d343

If I comment out the throw new Exception line, then the MixedPropertyFetch error goes away.

[psalm-github-bot[bot]]

I found these snippets:

https://psalm.dev/r/f7ffc1d343

<?php
/** @var object{Wrapper: object{
 *     Header: object{UID: string, Status: string}
 * }} $resp
 */
$result = $resp->Wrapper;

if ($result->Header->Status !== "OK") {
    throw new Exception("Response failed");
}

return $result->Header->UID;

Psalm output (using commit a75d26a):

INFO: MixedPropertyFetch - 12:8 - Cannot fetch property on mixed var $result->Header

[rzvc]

I have the exact same issue.