Tests for proposal-json-superset

[gibson042]

tc39/proposal-json-superset#9

Allow non-ASCII LineTerminator characters (U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR) in string literals.

[ljharb]

Duplicate of #1543; is there anything here that could be added there?

[mathiasbynens]

I’m fine with either #1543 or this patch.

[mathiasbynens]

features.txt needs to be updated:

# ECMAScript ⊃ JSON
# https://github.com/tc39/proposal-json-superset
json-superset

And then the tests need the json-superset tag.

[rwaldron]

@gibson042 this is good to go with or without the update to features.txt and addition of json-superset (I can take care of it if you don't have time).

[leobalter]

Bikeshedding some ideas to follow up in a new patch:

• single quote strings
• the .length property being affected by these characters
• the .codePointAt returns
• syntax being constructed through eval where a line separator is not allowed... e.g.: eval('async \u2029 function fn() {}') and eval('async \u2028 function fn() {}')

[rwaldron]

👍