app()->make($className) returns type *NEVER*

[levu42]

• Larastan Version: 2.3.4
• --level used: 8

Description

I have in my code this section:

        $model = $this->getModelClassName();
        $object = app()->make($model);

        \PHPStan\dumpType($object);

        if (! $object instanceof Model) {
            throw new ReflectionException("$model is not an instance of " . Model::class);
        }

where $this->getModelClassName() has a PHPDoc return type of class-name<Model>, and then the dumpType shows me: Dumped type: *NEVER*.

I guess, it's related to #1451 since it only happens since I upgraded from 2.3.0 -> 2.3.4.

The actual false positive error triggered in this section is by the way Unreachable statement - code above always terminates. for the code below the instanceof / throw section.

[szepeviktor]

Hello @levu42 👋🏻

Yes, the default type may be incorrect.
https://github.com/nunomaduro/larastan/blob/f5103aaa9ebe050689b7c4f7870563bb2de33f92/src/ReturnTypes/AppMakeHelper.php#L48

[levu42]

@szepeviktor Thanks for your fast reply!

In this case:

class X {
    /** @return class-string<Model> */
    private function getModelClassName(): string {...}

    private function foo(): void
    {
         $model = $this->getModelClassName();
         $object = app()->make($model);
    }

When I dump the type of $model I get Dumped type: class-string<Illuminate\Database\Eloquent\Model>.

The code you linked looks to me like the only way it returns NeverType is by $expr instanceof String_ evaluating to false. I don't know anything really about the PHPStan internals, so I have no clue how to fix that best, but from my understanding, class-string is a special case of string, so this should evaluate to true, not false.