Psalm: false-positive more specific type

[azjezz]

see https://github.com/azjezz/psl/pull/104/checks?check_run_id=1490660317

[psalm-github-bot[bot]]

Hey @azjezz, can you reproduce the issue on https://psalm.dev ?

[weirdan]

I believe this is a minimal reproducer: https://psalm.dev/r/08b0d969e9

[psalm-github-bot[bot]]

I found these snippets:

https://psalm.dev/r/08b0d969e9

<?php
namespace Psl\Collection;
use IteratorAggregate;

/**
 * @template Tk of array-key
 * @template Tv
 * @extends IteratorAggregate<Tk, Tv>
 */
interface CollectionInterface extends IteratorAggregate {
    /**
     * @psalm-param Tk $k
     * @psalm-return Tv
     */
    public function at($k);
}

/**
 * @template Tk of array-key
 * @template Tv
 *
 * @extends CollectionInterface<Tk, Tv>
 */
interface AccessibleCollectionInterface extends CollectionInterface {}

/**
 * @template Tk of array-key
 * @template Tv
 *
 * @implements AccessibleCollectionInterface<Tk, Tv>
 */
abstract class Map implements AccessibleCollectionInterface
{  
    /**
     * @psalm-param  Tk $k
     * @psalm-return Tv
     */
    public function at($k) { /** @var Tv */ return 1;  }
}

Psalm output (using commit 0411049):

ERROR: MoreSpecificImplementedParamType - 38:24 - Argument 1 of Psl\Collection\Map::at has the more specific type 'Tk:Psl\Collection\Map as array-key', expecting 'array-key' as defined by Psl\Collection\CollectionInterface::at

[azjezz]

do you think it makes sense to revert https://github.com/vimeo/psalm/commit/6ed7a811463537d27f6669d6fd52946d0426621b?

I'm making sure that PSL always has a successful build.

The bug with Psl\Collection + generics has appeared multiple times here:

• #3760
• #2849
• #2581
• #2569
• #2556

so in my opinion, Psl\Collection is a great real-world test case for generics in Psalm.

[muglug]

Agreed – I disabled tests because at the time there were bugs in PSL, now the shoe is on the other foot.

This was broken by https://github.com/vimeo/psalm/commit/15a5bd5e295d3dcf4f9e97fce9b6b6f3e01fed28

[muglug]

To be clear, though, this is a different bug than those others

[muglug]

This is one of those fun times where a "straightforward" refactor exposed an underlying bug that had been there for a while – that after stubs have been scanned, all explicit _and_ implicit (via inheritance) implemented interfaces were re-evaluated. It was the implicit ones that were causing trouble.

I've re-enabled PSL integration tests with 5fc2b4e04

[azjezz]

Thank you for the quick fix.

but it seems there is still an issue with getIterator ( I see you added @psalm-suppress for it in the tests ), is the error valid? or awaiting a fix? https://github.com/azjezz/psl/runs/1498607963