module.exports = {
  conditions: [''],
  name: 'IdentifierStart',
  rules: [
    `UnicodeIDStart`,
    `UnicodeEscapeSequence`,
  ],
  handlers: [
    `$$ = $1;`,
    `$$ = $1;`, // TODO: unicode with id start
  ],
  subRules: [
    require('./UnicodeEscapeSequence'),
  ],
};

@@ -121,16 +121,34 @@
 uence%60,%0A
+    %60$%60,%0A    %60_%60,%0A
   %5D,%0A  h
@@ -221,16 +221,48 @@
 d start%0A
+    %60$$ = $1;%60,%0A    %60$$ = $1;%60,%0A
   %5D,%0A  s

add dollar and underscore