Conditional return types reference another method

[Wulfheart]

Given the following file

<?php
final class Sitemap
{
    /**
     * @var array <string, SitemapPage>
     */
    private array $pages = [];

    public function containsPage(PageId $pageId): bool
    {
        return array_key_exists($pageId->getAsString(), $this->pages);
    }

    public function getPage(PageId $pageId): ?SitemapPage
    {
        return $this->pages[$pageId->getAsString()] ?? null;
    }
}

I would like to somehow define that the getPage function is not null if the result of the containsPage is true. Just like the IDE recognises it with null checks. Is this somehow possible?

[orklah]

That should help: https://psalm.dev/docs/annotating_code/adding_assertions/#asserting-return-values-of-methods

[Wulfheart]

Thank you really much. However, it does not seem to work when using something like @psalm-assert-if-true SitemapPage $this->getPage($pageId)

[orklah]

oh sorry, I hadn't noticed that you had an argument in there. That's not supported for now