code: function scanJsxToken() {
    skipComments();
    let beginIndex = index;
    switch (currentCharCode) {
      case 34:  // "
      case 39:  // '
        return scanJsxStringLiteral(beginIndex, currentCharCode);
      case 62:  // >
        next();
        return createToken(CLOSE_ANGLE, beginIndex);
      // case 123:  // {
      // case 125:  // }
    }
  
    if (!isIdentifierStart(currentCharCode)) {
      return scanToken();
    }
    next();
    while (isIdentifierPart(currentCharCode) || currentCharCode === 45) {  // '-'
      next();
    }
    let value = input.slice(beginIndex, index);
    return new JsxIdentifierToken(getTokenRange(beginIndex), value);
  }
docs: Used to scan for a JSXIdentifier.