Expects T:fn-a as object, object provided

[simPod]

https://psalm.dev/r/b70f1af09b

callback expects an object and I passed an object. It is not very clear what is the issue in the code / psalm bug?

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/b70f1af09b

<?php

interface Serializer
{
    /**
     * @param mixed $data
     */
    public function serialize($data): string;

    /**
     * @return mixed
     *
     * @psalm-template T
     * @psalm-param class-string<T> $type
     * @psalm-return T
     */
    public function deserialize(string $data, string $type);
}

/**
 * @template T of object
 * @psalm-param    T $serializable
 * @psalm-param    callable(T, T): void $cmp
 */
function a(Serializer $serializer, $serializable, callable $cmp) : void
{
    $serialized = $serializer->serialize($serializable);

    $deserialized = $serializer->deserialize($serialized, get_class($serializable));

    $cmp($serializable, $deserialized);
}

Psalm output (using commit ed6fdaa):

ERROR: InvalidArgument - 31:25 - Argument 2 expects T:fn-a as object, object provided

[muglug]

Simplified: https://psalm.dev/r/93c8173378

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/93c8173378

<?php

/**
 * @template T of object
 * @psalm-param T $obj
 * @return T
 */
function a(string $str, object $obj) {
    $class = get_class($obj);
    return deserialize_object($str, $class);
}

/**
 * @psalm-template T
 * @psalm-param class-string<T> $type
 * @psalm-return T
 * @psalm-suppress InvalidReturnType
 */
function deserialize_object(string $data, string $type) {}

Psalm output (using commit 924f6b6):

ERROR: InvalidReturnStatement - 10:12 - The inferred type 'object' does not match the declared return type 'T:fn-a as object' for a

ERROR: InvalidReturnType - 6:12 - The declared return type 'T:fn-a as object' for a is incorrect, got 'object'

INFO: UnusedParam - 19:36 - Param $data is never referenced in this method

INFO: UnusedParam - 19:50 - Param $type is never referenced in this method