How to activate generic typing inference on function intersection type?

[Athelian]

Hello, sorry if this is a simple question

I am really struggling to figure out how to activate the second version of this set function, see
flowtry

The definition is taken straight from here

To me I should not be getting an explicit any on newAny. I also tried activating the generic version using underbar. From Flow docs:

If you only want to specify some of the type arguments, you can use _ to let flow infer a type for you:

Please someone let me know if they know how to properly use functions like this.

[Brianzchen]

Both links are the same. Not really sure what your issue is. Can you review it a bit then get back to me?

[Athelian]

Thanks for the reply.

To me I'm seeing two definitions for set in this library.

In this FlowTry:
Line 14: define a function set

Line 16: define a variable setTyped, annotated with type Set and equal to the set function
Line 17: define a variable setUntyped, the same as above but unannotated

Result:
setTyped's return type is always any
setUntypeds return type uses generics correctly.

When I invoke lodash.set with these typings in a production repo, every return is marked as any.

I would like to know how to invoke lodash.set using the definition:
(<T: void | null>( object: T, path?: ?string, value?: ?any ) => T)

and not using the definition:
((object: Object, path?: ?string, value: any) => Object)

[pascalduez]

Side note: Object does not exist anymore in Flow, and is resolving to any, so you'd want to avoid using it, it gives false assumptions.

[pascalduez]

Also <T: void | null> is quite weird, it's a type constraint and means you'd only allow void | null types.

[Athelian]

Also <T: void | null> is quite weird, it's a type constraint and means you'd only allow void | null types.

To me this is saying "Do not add anything in here. If this is empty, then it will activate Flow's type inference system and we will infer the return type".

But I cannot get the type inference to activate in the first place with this current definition.