Verify shared instance properties -> class properties about javascript

[lemonmade]

Welp, I think the different issues are getting mixed up :P I think we are on the same page and #138 partially covers what we are after in terms of shared literal properties.

[GoodForOneFare]

@lemonmade this is another one that'll now throw an error during decaf. FWIW, there's 80+ affected files, so I think there's a strong case for automating a fix.

[lemonmade]

What do you think the automated fix should look like? Should we add a Foo.prototype.bar = 123 to decaf?

[GoodForOneFare]

Assuming that we split all classes into separate files (#125), I think we can insert any private stuff before the class definition. So:

class Shopify.AutocompleteV2
  LIST_CLASS = '.js-autocomplete-suggestions'
  PIXELS_FROM_BOTTOM_TO_INFINITE_SCROLL = 500
  ERROR_DISPLAY_TIME = 5000

  constructor: (node, @renderer, @options={}) ->

becomes

const LIST_CLASS = '.js-autocomplete-suggestions'
const PIXELS_FROM_BOTTOM_TO_INFINITE_SCROLL = 500
const ERROR_DISPLAY_TIME = 5000

class Shopify.AutocompleteV2
  constructor: (node, @renderer, @options={}) ->

[GoodForOneFare]

Heh. Yeah, prettymuch what you just raised in #157 :)

[lemonmade]

👍

[GoodForOneFare]

The mainline merge picked up a fix from Julian for this (https://github.com/shopify/decaf/blame/master/test/test.js#L1209). Closing.