[x3d-public] impact for JSON: ES6 and duplicate object literal properties

[Don Brutzman]

Hmmm, maybe OK?  Here are some tests.

On 12/18/2016 6:01 AM, yottzumm at gmail.com wrote:
> Note that in ES6, even in strict mode, the following will not cause an error:
>
> var books = {
>                 title: “Understanding ECMAScript 6”,
>                 title: “JavaScript: The Good, the Bad and the Ugly”
> };
>
> However,
>
> books.title === “JavaScript: The Good, the Bad and the Ugly”

Might you know the ES6 specification paragraph?

	http://www.ecma-international.org/ecma-262/6.0/#sec-terms-and-definitions-object

Wondering why they might deviate from prior strictness in JSON object model - duplicate keys can't be represented as an object.  Perhaps there is a site or online discussion that covers this?

> This will be important for JSON linters to catch, unless we want to do streaming JSON (we don’t).

how about jslint, jshint and X3DJSONLD ?

	http://jsonlint.com

	http://jshint.com

	https://github.com/coderextreme/X3DJSONLD

I had trouble getting jsonlint or jshint to operate on your example, they balked mysteriously until replacing left-quote/right-quote characters.  Also jslint failed silently under IE.

This strict version of your example works:
==============
{ "books":{

     "title":"Understanding ECMAScript 6",

     "title2":"JavaScript: The Good, the Bad and the Ugly"
   }
}
==============

jslint and jshint report "duplicate key" for:

==============
{ "books":{

     "title":"Understanding ECMAScript 6",

     "title":"JavaScript: The Good, the Bad and the Ugly"
   }
}
==============

if ES6 checkbox is selected, jslint still reports: Duplicate 'title'.

So maybe we are OK on this issue?

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman