$ cat test.js
require('shift-parser').default('"\\u{110000}"', {earlyErrors: false})
$ node test.js 
/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:685
            throw this.createILLEGAL();
            ^

Error: [1:4]: Unexpected "{"
    at new JsError (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:163:81)
    at GenericParser.createError (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:285:14)
    at GenericParser.createILLEGAL (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:253:53)
    at GenericParser.scanUnicode (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:685:24)
    at GenericParser.scanStringEscape (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:1225:43)
    at GenericParser.scanStringLiteral (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:1305:40)
    at GenericParser.advance (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/tokenizer.js:1465:23)
    at GenericParser.parseScript (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/parser.js:241:29)
    at Object.parse (/home/lydell/bugs/shift-unicode/node_modules/shift-parser/dist/index.js:115:43)
    at Object.<anonymous> (/home/lydell/bugs/shift-unicode/test.js:1:94)