Do we even need this dynamic return type extension at all ? Prophecy defines the return type of those methods: https://github.com/phpspec/prophecy/blob/53ab8cee442a4e9f9827aaec92b023af841783c5/src/Prophecy/Prophecy/ObjectProphecy.php#L70-L72

I think the improvement released in phpstan 2.1.3 and 1.12.17 might make it work out of the box.

@stof Thx for the fast response. Looking at the code I would have expected the same but the result looks unexpected, it returns some strange return type without the extension.

Property                                                                                                                           
         JanGregor\Prophecy\Test\StaticAnalysis\Test\ObjectProphecy\WillImplementTest::$prophecy                                            
         (Prophecy\Prophecy\ObjectProphecy<JanGregor\Prophecy\Test\StaticAnalysis\Src\Bar&JanGregor\Prophecy\Test\StaticAnalysis\Src\Foo>)  
         does not accept                                                                                                                    
         $this(JanGregor\Prophecy\Test\StaticAnalysis\Test\ObjectProphecy\WillImplementTest).                                               
         🪪  assign.propertyType 

See #367 ( same as this branch but without the extension )

@stof Maybe still related to your issue here: phpstan/phpstan#8439

@stof The @phpstan-this-out is not going to work in a fluent call. It'd have to be @return static<T&U> as well.

this looks like a bug in phpstan. It seems to resolve static<T&U> using the class of where the method is called (i.e. JanGregor\Prophecy\Test\StaticAnalysis\Test\ObjectProphecy\WillImplementTest) instead of on what the method is called (ObjectProphecy)

@stof @ondrejmirtes I tried to put all in a small case on phpstan playground. Think this should be the current state without the extension:

https://phpstan.org/r/ccb8b2d4-fc46-4138-a4fd-a93548b52d18

Replace @return $this with @return static<T&U> I get one error away but not the others:

https://phpstan.org/r/9111aa05-f79a-4b51-8ac5-6ab554551fb2

@ondrejmirtes @stof Best Result seems to be use self or ObjectProphecy instead of static: https://phpstan.org/r/a2dc1d8a-1a83-4b1a-949a-b23ae7c4cf28

Update using @template-covariant we would be here then: https://phpstan.org/r/057747fe-f1d4-4051-8407-d81b7127a668.

With some hacks (@template-covariant to @template) I would be here: https://phpstan.org/r/c2ea3768-3c1a-462f-9ae9-f3c64e4cf462 . With no errors but not sure about that solution?

Alright, what I figured out is that the extension WillExtendOrImplementDynamicReturnTypeExtension can be greatly simplified to:

    public function getTypeFromMethodCall(
        Reflection\MethodReflection $methodReflection,
        Node\Expr\MethodCall $methodCall,
        Analyser\Scope $scope
    ): ?Type\Type {
        $args = $methodCall->getArgs();
        if (0 === \count($args)) {
            return null;
        }

        $calledOnType = $scope->getType($methodCall->var);
        $templateObjectType = $calledOnType->getTemplateType(Prophecy\ObjectProphecy::class, 'T');

        $objects = [$templateObjectType];
        $argumentType = $scope->getType($args[0]->value);
        $objects[] = $argumentType->getClassStringObjectType();

        return new Type\Generic\GenericObjectType(
            Prophecy\ObjectProphecy::class,
            [
                Type\TypeCombinator::intersect(...$objects),
            ],
        );
    }

No need to make it more complicated than that. But the build still fails with that. I figured out that when I remove @phpstan-this-out static<T&U> from above public function willImplement($interface), the build starts passing correctly.

So the bug is in PHPStan and it's about not properly supporting static<T&U> in @phpstan-this-out. I'm going to take a look at that.

@ondrejmirtes thx, let me know If I can test something out.

@ondrejmirtes see phpstan/phpstan#12575 where I reported an issue when reproducing this without a type extension

Do we even need this extension at all or are the stubs (replacing the prophecy annotations to avoid using static<...> to work around the bug) enough to pass the test ?

@stof you are right my current stubs would be enough. Only with the extension the call $templateObjectType = $calledOnType->getTemplateType(Prophecy\ObjectProphecy::class, 'T'); fails because of the static<T&U>.

See #369

replaced by: #369