I'm trying to call a function being passed to me in a Js.t({..}) and it's not being called as I expected.

ReasonML Code:

"onNavigate": (query, event) => props##applyFilter(. query, event),

Function in JS Code side:

applyFilter: (query, event = {}) => {
  // snip
};

I think what is happening is the second arg event is being assigned a default value so when this function is called with a currying style that arg is not set properly.

So now another interesting thing is, when I call the function in a uncurried way:

"onNavigate": (query, event) => props##applyFilter(. query, event),

I get the following warning:

Alert unused: Unused attribute [@u]

Which I believe is a false positive because in this situation the function is now called correctly!

So it seems that there are 2 main issues:

1. Default values for function args breaks the currying system (at least when the functions are a property of a JS object)
2. When calling a function uncurried, if that function is in a Js.t({..}) you'll get a warning about an unused attribute [@u] (playground link)