generate firestore token for backoffice user

auth.ts

import * as functions from 'firebase-functions';
import * as admin from 'firebase-admin';
import { compare } from 'bcryptjs';
import { Merchant } from '../state';

interface AuthRequest {
  username: string;
  password: string;
}

export const authMerchant = functions.https.onCall(async (data: AuthRequest, context) => {
  const { username, password } = data;
  if (username) {
    const qry = admin.firestore().collection('merchants').where('loginUserName', '==', username.toUpperCase());
    const sn = await qry.get();
    if (sn.size > 0) {
      const d = sn.docs[0];
      const { password: hashed } = d.data() as Merchant;

      const same = await compare(password, hashed)
      const auth = admin.auth();
      if (same) {
        const ftoken = await admin.auth().createCustomToken(d.id, {
          merchant: true,
        });

        return {
          success: true,
          token: ftoken,
        };
      }

      return {
        success: false,
        error: 'invalidCredential',
      };
    }
  }

  return {
    success: false,
    error: 'userNotFound',
  };
});