Inconsistent behavior with template-extends and template constraints

[simitter]

Hello,

If a class extends a template and puts in the constraints directly in the extends tag seems to work fine.
If template extends derives the constraints from another template psalm reports a MixedArgumentTypeCoercion

It seemed to work in the 4.4 versions.
Is this a bug or am i missing something?

https://psalm.dev/r/6258a74579

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/6258a74579

<?php

/**
 * @psalm-template T
 */
abstract class Base {}

/**
 * @psalm-template T2 of int|float
 *
 * @template-extends Base<T2>
 */
final class NotWorking extends Base {}

/**
 * @template-extends Base<int|float>
 */
final class Working extends Base {}

/** @psalm-suppress UnusedParam */
function testNotWorking(NotWorking $notWorking): void {}

/** @psalm-suppress UnusedParam */
function testWorking(Working $working): void {}

testNotWorking(new NotWorking());
testWorking(new Working());

Psalm output (using commit 86ba3b0):

INFO: MixedArgumentTypeCoercion - 26:16 - Argument 1 of testNotWorking expects NotWorking<float|int>, parent type NotWorking provided

[githoober]

I have a similar case. The template info is lost when checking for an instance with 'instanceof'

https://psalm.dev/r/a73291657c

https://psalm.dev/r/9247b4d5d6

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/a73291657c

<?php

class Element {}

/**
* @template E of Element
*/
class ElementList {}

/**
* @param Element|ElementList<Element>|mixed $data
*/
function test($data): void
{
    if ($data instanceof Element) {
    } else if ($data instanceof ElementList) {
        acceptList($data);
    }        
}

/**
* @param ElementList<Element> $list
*/
function acceptList(ElementList $list): void
{
    echo get_class($list);
}

Psalm output (using commit e93e532):

INFO: MixedArgumentTypeCoercion - 17:20 - Argument 1 of acceptList expects ElementList<Element>, parent type ElementList provided

https://psalm.dev/r/9247b4d5d6

<?php

class Element {}

class ChildElement extends Element {}

/**
* @template E of Element
*/
class ElementList {}

/**
* @param ChildElement|ElementList<ChildElement>|mixed $data
*/
function test($data): void
{
    if ($data instanceof ChildElement) {
        
    } else if ($data instanceof ElementList) {
        acceptList($data);
    }        
}

/**
* @param ElementList<ChildElement> $list
*/
function acceptList(ElementList $list): void
{
    echo get_class($list);
}

Psalm output (using commit e93e532):

INFO: MixedArgumentTypeCoercion - 20:20 - Argument 1 of acceptList expects ElementList<ChildElement>, parent type ElementList provided

[githoober]

This behavior is not present in psalm 4.4, shows up in 4.5 and continues in 4.6.