@directive on a function level fails to compile with async and multiple parameters

[reebalazs]

• Is it a bug? Usage questions should often be asked in the forum instead.
• Concise, focused, friendly issue title & description.
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On version 12.0.0-rc.2

I don't think this feature of using @directive on a function is documented. Anyway it works well and it's useful for frameworks like NextJs.

The problem seems to be the parameter parsing with async functions.

So this fails to compile - Await on expression not in async context error for the line with await.

let f =
  @directive("'use cache'")
  async (p1, ~p2, ~p3) => {
    await Promise.make((resolve, _reject) => resolve((p1, p2, p3))
  }

While this compiles (with zero or one parameters):

let f =
  @directive("'use cache'")
   async (p1) => {
    await Promise.make((resolve, _reject) => resolve((p1)))
  }

And this also compiles (without async):

let f =
  @directive("'use cache'")
  (p1, ~p2, ~p3) => {
    Promise.make((resolve, _reject) => resolve((p1, p2, p3)))
  }

So zero or one parameters compile with async, more than one parameter fails to compile with async. While without async, any number of parameters compile correctly. So I can find a workaround by not using async, if I need multiple parameters. However this looks like a bug.