message: generate id util function
diff: @@ -3,7 +3,19 @@ import * as _ from "lodash";
  export const serverTimestamp = admin.firestore.FieldValue.serverTimestamp;
  import { sendEmail } from "./email";
  import { hasAnyRole } from "./auth";
  -export default { sendEmail, serverTimestamp, hasAnyRole };
  +
  +var characters =
  + "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  +export function generateId(length) {
  + var result = "";
  + var charactersLength = characters.length;
  + for (var i = 0; i < length; i++) {
  + result += characters.charAt(Math.floor(Math.random() * charactersLength));
  + }
  + return result;
  +}
  +
  +export default { generateId, sendEmail, serverTimestamp, hasAnyRole };
  export const replacer = (data: any) => (m: string, key: string) => {
  const objKey = key.split(":")[0];
  const defaultValue = key.split(":")[1] || "";
  