Support templated `@phpstan-type`

[AnrDaemon]

I have this block in my code:

<?php

/**
 * API interop.
 *
 * @template T
 * @phpstan-type ResponsePayload array{
 *  data: T,
 *  links: ?array{
 *      self: string,
 *      first: string,
 *      last: string,
 *      next: string,
 *  },
 *  pager: ?array{
 *      total: int,
 *      current: int,
 *      limit: int,
 *  },
 * } API response template
 */
class X {
/** @return ResponsePayload<array> */
function x(): array {
    return ['data' => []];
}

function y() {
    $x = $this->x()['data'];
}
}

I can't complete the data key in the y() function, unless I remove the specifier.

What I'm doing wrong?

[bmewburn]

The template is associated with the class, not the type alias.
So it's /** @return ResponsePayload */ and an instance of the class may be X<array> . There seems to be a bug though where T in ResponsePayload isn't getting resolved to array for the return type of X<array>::x().

[AnrDaemon]

But that's making it p.much useless.

[bmewburn]

I don't think phpstan supports this. Will leave it open as a feature request.

[AnrDaemon]

Judging by https://phpstan.org/blog/generics-by-examples, @template is bound to the docblock it is defined in and to all the children the block is relevant to. Which, in case of a class, means what you said - but that's not a whole story.

I've opened a discussion. Let's see what people know.