Fix inferred union types for Ds Map::get() and Map::remove()

[simPod]

👋 can you guide me with this please?

I'm passing Map<int, int|string> into the function.

However, return type of get(0) call on the map is resolved as int. I'd expect int|string.

/** @param Map<int, int|string> $a */
public function mapGetUnionType(Map $a) : void
{
	assertType('int|string', $a->get(0));
}

Expected :'int|string'
Actual   :'int'

Map stub is

/**
 * @template TKey
 * @template TValue
 * @implements Collection<TKey, TValue>
 */
final class Map implements Collection
{
    /**
     * @param iterable<TKey, TValue>|null $values
     */
    public function __construct(?iterable $values = null)
    {
    }

So I believe I'm saying that TValue is int|string.

Map::get()'s signature is

/**
 * @template TDefault
 * @param TKey $key
 * @param TDefault $default
 * @return TValue|TDefault
 * @throws OutOfBoundsException
 */
public function get($key, $default = null)

so get(0) should return TValue (int|string). Or not? Thanks!

[ondrejmirtes]

No idea what's wrong, What happens if you pass in $a->get('foo')?

[ondrejmirtes]

Oh, I realized what's wrong. There's this extension: https://github.com/phpstan/phpstan-src/blob/master/src/Type/Php/DsMapDynamicReturnTypeExtension.php

You can try to remove it and see what happens.

[simPod]

You're right. Would it make sense to drop it then? Like in the commit 👆

[simPod]

OutOfBounds exception is thrown if I remember correctly

[ondrejmirtes]

You're right. So the @return TValue|TDefault is wrong if the second argument is not present. So the extension must be modified and not deleted.

[ondrejmirtes]

Looks fine, thank you!