Fable: [ERROR] This expression was expected to have type 'obj' but here has type 'obj -> obj'

[Pauan]

Repro code

module Main

open Fable.Core
open Fable.Core.JsInterop

let foo: obj = jsNative?bar

Description

I get this error:

ERROR in ./Main.fsproj
/Main.fs(6,15,6,27) : error FSHARP: This expression was expected to have type
    'obj'    
but here has type
    'obj -> obj'    
 @ multi babel-polyfill ./Main.fsproj

Is this expected behavior? I thought that the ? syntax can be used for both property lookups and method calls, but it seems not.

Related information

• fable-compiler version: [email protected]
• fable-core version: [email protected]
• Operating system: Debian GNU/Linux Testing 64-bit

[alfonsogarciacaro]

This is a trick I had to do to make dynamic properties directly applicable. So you can do foo?bar(1,2) instead of using an intermediate operator like before foo?bar$(1,2). I've filled an F# language suggestion to avoid the need of having the result of ? be of obj->obj type.

For now, you can just use dynamic cast in these cases: let foo: obj = !!myObj?bar

BTW, jsNative will throw an exception. I guess you want something else there.

[Pauan]

The jsNative was just to create the smallest possible repro code, in a real app it would use proper JS interop.

Thanks for filing an issue! :heart: