Hi,

Version: VS 2015/TS 1.6.2

There are few issues with intellisense in the following snippet

const f = (foo: (bar: string[]) => void) => { };

f(a=> {

    const aa = a[0];
    aa.charAt(0); // Okay: inferred as string
});

f(([a, b]) => {

    a.charAt(0); // Not okay: inferred as `any`
});

Points to note:

• Hovering over [a, b] in the very last function call shows the type of a to be any and the type of b to be string.
• Furthermore, this is not constant. Adding b.charAt(0); to the function body, and then hovering over a, b shows a to be string and b to be any.
• In either case, there is no completion for either a or b, when they are dotted off.

This is only a problem with quick info and completion. If I were to change the function to have a number array parameter

const f = (foo: (bar: number[]) => void) => { };

Then all charAt calls are underlined in red as expected and the file fails to compile.