Testing for a feature of regex compilation in IE11

Question

I would like to test for Unicode Regex Property Escapes to avoid compiling a broken regular expression in browsers that do not support it (for example IE11). Ideally, I\'d like

Answer 1

This works in Firefox or Safari; should be okay in IE11:

let regex = /somereplacementregex/;
try
{
    regex = new RegExp ("\\p{Emoji_Modifier_Base}\\p{Emoji_Modifier}?|\\p{Emoji_Presentation}|\\p{Emoji}\\uFE0F", "gu");
}
catch (e) { }
//
// use regex...
console.log (regex);

Answer 2

If you feel comfortable with something like Function or eval, and a try/catch...something like this should work:

try { 
  return new Function('', 'return /\\p{Script=Greek}/u;')() 
} catch(e) { return /asdf/g;}

Note you have to escape the \\p because it's contained in a string now. Tested this on IE11 and it worked (fell back without a fatal parsing error)