User defined assertions works incorrectly for generic iterable types

[klimick]

Lets take a look at this https://psalm.dev/r/12ed2787e9
or this https://psalm.dev/r/a4ab076a44
example.

Works fine. As expected.

But if go deeper and try to assert generic type like list<int> then psalm lose types:

psalm-assert-if-true: https://psalm.dev/r/58dbc19d8a
psalm-assert: https://psalm.dev/r/4c25ed702c

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/12ed2787e9

<?php

/**
 * @template A
 */
final class Type {}

/**
 * @template T
 *
 * @param Type<T> $t
 * @psalm-assert-if-true T $toCheck
 */
function isTypeOf(Type $t, mixed $toCheck): bool
{
    throw new RuntimeException('???');
}

/** @var Type<int> $numberT */
$numberT = null;

/** @var mixed $mixed */
$mixed = null;

if (isTypeOf($numberT, $mixed)) {
    /** @psalm-trace $number */
	$number = $mixed; // is int. awesome.
}

Psalm output (using commit 44f8d71):

INFO: Trace - 27:2 - $number: int

https://psalm.dev/r/a4ab076a44

<?php

/**
 * @template A
 */
final class Type {}

/**
 * @template T
 *
 * @param Type<T> $t
 * @psalm-assert T $toCheck
 */
function assertTypeOf(Type $t, mixed $toCheck): void
{
    throw new RuntimeException('???');
}

/** @var Type<int> $numberT */
$numberT = null;

/** @var mixed $mixed */
$mixed = null;

assertTypeOf($numberT, $mixed);

/** @psalm-trace $number */
$number = $mixed; // is int. awesome.

Psalm output (using commit 44f8d71):

INFO: Trace - 28:1 - $number: int

https://psalm.dev/r/58dbc19d8a

<?php

/**
 * @template A
 */
final class Type {}

/**
 * @template T
 *
 * @param Type<T> $t
 * @psalm-assert-if-true T $toCheck
 */
function isTypeOf(Type $t, mixed $toCheck): bool
{
    throw new RuntimeException('???');
}

/** @var Type<list<int>> $numbersT */
$numbersT = null;

/** @var mixed $mixed */
$mixed = null;

if (isTypeOf($numbersT, $mixed)) {
    /** @psalm-trace $numbers */
	$numbers = $mixed; // is array<array-key, mixed>. but should be list<int>.
}

Psalm output (using commit 44f8d71):

INFO: Trace - 27:2 - $numbers: array<array-key, mixed>

https://psalm.dev/r/4c25ed702c

<?php

/**
 * @template A
 */
final class Type {}

/**
 * @template T
 *
 * @param Type<T> $t
 * @psalm-assert T $toCheck
 */
function assertTypeOf(Type $t, mixed $toCheck): void
{
    throw new RuntimeException('???');
}

/** @var Type<list<int>> $numbersT */
$numbersT = null;

/** @var mixed $mixed */
$mixed = null;

assertTypeOf($numbersT, $mixed);

/** @psalm-trace $numbers */
$numbers = $mixed; // is mixed. Not even array<array-key, int>.

Psalm output (using commit 44f8d71):

INFO: MixedAssignment - 28:1 - Unable to determine the type that $numbers is being assigned to

INFO: Trace - 28:1 - $numbers: mixed

[klimick]

Hmmmmm.

This example https://psalm.dev/r/205e1d64ea contains generic assertion too. But it is working.

It seems issue only with iterable type.

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/205e1d64ea

<?php

/**
 * @template A
 */
final class Type {}

/**
 * @template T
 *
 * @param Type<T> $t
 * @psalm-assert-if-true T $toCheck
 */
function isTypeOf(Type $t, mixed $toCheck): bool
{
    throw new RuntimeException('???');
}

/**
 * @template T
 */
final class Foo {}

/** @var Type<Foo<int>> $fooT */
$fooT = null;

/** @var mixed $mixed */
$mixed = null;

if (isTypeOf($fooT, $mixed)) {
    /** @psalm-trace $number */
	$number = $mixed; // is int. awesome.
}

Psalm output (using commit 594ef4f):

INFO: Trace - 32:2 - $number: Foo<int>

[weirdan]

Then it's possibly related to #5310

[klimick]

Seems a problem at this place:

psalm/src/Psalm/Storage/Assertion.php

Line 63 in 110c9ef

$rule_token[0] = $first_type->getKey();

getKey returns list instead of list<T>

Can we change it to getId? @weirdan

[orklah]

@klimick please try it in a PR, we'll see how CI reacts :)