Pagerfanta template causing error in psalm

Question

I am trying to move from phpdoc to psalm and I am getting weird error with its template based returns.

class Message {}

interface FooInterface
{
    /** @return Pagerfanta|Message[] */
    public function getMessages(): Pagerfanta;
}

This is showing TooManyTemplateParams error even though I am setting exactly one and Pagerfanta also has exactly one parameter set in its definition.

Even psalm online validator is showing this error: https://psalm.dev/r/68b22e896f

What am I doing wrong?

Answer 1

The Pagerfanta class (as presented in the linked snippet) does indeed have no type parameters - it has 0 @template tags.

You need to upgrade to a later version of Pagerfanta that has this issue fixed. 2.7.2 seems to have the fix in place.

Sidenote: Pagerfanta|Message[] form is a legacy PHPStorm syntax and I would recommend to avoid it due to ambiguity.