javascript/es6 format doesn't handle newlines in comments

[Zkrgu]

Comments are inserted as a line comment here:

style-dictionary/lib/common/formats.js

Line 643 in 737a02b

return comment ? to_ret.concat(`// ${comment}`) : to_ret;

This has previously been fixed for some formats in #953

Example of failing token

{
    "token": {
        "value": 0,
        "comment": "This\nis not valid"
    },
    "another": {
        "value": 1,
    }
}

This fails to build with

SyntaxError: Missing semicolon. (6:3)
  4 |
  5 | export const token = 0; // This
> 6 | is not valid
  7 | export const another = 0;
  8 |

[jorenbroekema]

I'm a bit conflicted about adding the enhancement flag, it's a missing feature imo but it could also be seen as a bug I suppose.

Anyways, the createPropertyFormatter format helper utility has a fix for this I introduced in v3 for the CSS / SCSS / LESS / Stylus formats, see the addComment helper. We can probably make that reusable in some way, and reuse it for our JS formats since they use a similar syntax for comments (// and /* */). Actually, I'm not sure // is valid in CSS, but at least the latter one they do share

PRs welcome