TODO

[othree]

• [x] Variable declaration
• [x] Import
• [x] Export
• [x] Class field
• [x] if/else
• [x] for in
• [x] for of
• [x] Expression
• [x] for
• [x] try/catch
• [x] switch
• [ ] switch discriminant
• [x] new
• [x] throw
• [x] exps
• [x] class mehods
• [x] Default function parameter
• [x] Array
• [x] Object
• [x] comma in array, object
• [x] Computed property
• [x] arrow function
• [x] function
• [x] Generator
• [x] async
• [x] call expression
• [x] Method definition
• [x] await
• [x] Template string
• [x] label
• [x] yield, return
• [ ] Before/after function parameter parens
• [ ] Paren
• [ ] Padding before }, ], )
• [x] Object shorthand
• [ ] Empty paren
• [ ] with

[othree]

arrow function
    [async] [params] => body

    => :: token before body
    params :: 
        if params.length
            if wrap by paren
                   token before params[0]
               else 
                   params[0]
        else
           token before `)` before `(` body
    async :: token before params

    test before params [async] [params]
    test before body   [params] => body

function
    [async] function [*] [id] [params] body

const a = () => {};
const b = arg => {};
const c = async (a, b) => {};
const d = async arg => {};

[othree]

https://github.com/eslint/espree/blob/6284e096ec0fd2e72bcc038609abea2bbc5020d2/lib/visitor-keys.js