implemented a simple backend for mobile banking

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true

.env

@@ -0,0 +1,3 @@
+PORT=8080
+DATABASE_URL=postgresql://kmobile_app_rw:kmobile@localhost:5432/kmobile_banking
+JWT_SECRET=supersecret

.gitignore

@@ -0,0 +1 @@
+node_modules/

.prettierignore

@@ -0,0 +1,2 @@
+node_modules
+dist

.prettierrc

@@ -0,0 +1,7 @@
+{
+    "semi": true,
+    "singleQuote": true,
+    "tabwidth": 2,
+    "printWidth": 80,
+    "trailingComma": "es5"
+}

eslint.config.js

@@ -0,0 +1,39 @@
+import eslintPluginPrettier from 'eslint-plugin-prettier';
+import eslintConfigPrettier from 'eslint-config-prettier';
+import js from '@eslint/js';
+import globals from 'globals';
+import { readFileSync } from 'fs';
+import path from 'path';
+
+export default [
+  {
+    ignores: ['node_modules', 'dist'],
+  },
+  {
+    files: ['**/*.js'],
+    languageOptions: {
+      ecmaVersion: 'latest',
+      sourceType: 'commonjs',
+      globals: {
+        ...globals.node,
+      },
+    },
+    plugins: {
+      prettier: eslintPluginPrettier,
+    },
+    rules: {
+      ...js.configs.recommended.rules,
+      'prettier/prettier': 'error',
+      'no-console': 'off',
+      'consistent-return': 'off',
+      'no-underscore-dangle': 'off',
+    },
+  },
+  {
+    settings: {
+      prettier: JSON.parse(
+        readFileSync(path.resolve('./.prettierrc'), 'utf-8')
+      ),
+    },
+  },
+];

package.json

@@ -0,0 +1,37 @@
+{
+  "name": "yume_js",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "dev": "nodemon src/server.js",
+    "start": "node src/server.js",
+    "lint": "eslint .",
+    "format": "prettier --write ."
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "description": "",
+  "dependencies": {
+    "bcrypt": "^6.0.0",
+    "cors": "^2.8.5",
+    "dotenv": "^16.5.0",
+    "express": "^5.1.0",
+    "jsonwebtoken": "^9.0.2",
+    "pg": "^8.16.0",
+    "pino": "^9.7.0",
+    "pino-http": "^10.4.0"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.28.0",
+    "eslint": "^9.28.0",
+    "eslint-config-prettier": "^10.1.5",
+    "eslint-plugin-prettier": "^5.4.1",
+    "globals": "^16.2.0",
+    "husky": "^9.1.7",
+    "lint-staged": "^16.1.0",
+    "nodemon": "^3.1.10",
+    "pino-pretty": "^13.0.0",
+    "prettier": "^3.5.3"
+  }
+}

src/app.js

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+const express = require('express');
+const cors = require('cors');
+const pinoHttp = require('pino-http');
+const { logger } = require('./util/logger');
+const routes = require('./routes');
+
+const app = express();
+
+app.use(cors());
+app.use(express.json());
+app.use(express.urlencoded({ extended: true }));
+
+// app.use(pinoHttp({ logger }));
+app.use('/api', routes);
+app.get('/health', (_, res) => res.send('server is healthy'));
+app.use((err, _req, res, _next) => {
+  logger.error(err, 'uncaught error');
+  res.status(500).json({ error: 'INTERNAL SERVER ERROR' });
+});
+
+module.exports = app;

src/config/config.js

@@ -0,0 +1,10 @@
+const dotenv = require('dotenv');
+const path = require('path');
+
+dotenv.config({ path: path.resolve(__dirname, '../../.env') });
+
+module.exports = {
+  port: process.env.PORT || 8080,
+  dbUrl: process.env.DATABASE_URL,
+  jwtSecret: process.env.JWT_SECRET,
+};

src/config/db.js

@@ -0,0 +1,20 @@
+const { Pool } = require('pg');
+const { dbUrl } = require('./config');
+const { logger } = require('../util/logger');
+
+const pool = new Pool({
+  connectionString: dbUrl,
+});
+
+pool.on('connect', () => {
+  logger.info('connected to Postgres database');
+});
+
+pool.on('error', (err) => {
+  logger.error(err, 'unexpected database pool error');
+});
+
+module.exports = {
+  query: (text, params) => pool.query(text, params),
+  pool,
+};

src/controllers/auth.controller.js

@@ -0,0 +1,25 @@
+const { validateUser } = require('../services/auth.service');
+const { generateToken } = require('../util/jwt');
+const { logger } = require('../util/logger');
+
+async function login(req, res) {
+  const { customerNo, password } = req.body;
+
+  if (!customerNo || !password) {
+    return res
+      .status(400)
+      .json({ error: 'customerNo and password are required' });
+  }
+
+  try {
+    const user = await validateUser(customerNo, password);
+    if (!user) return res.status(401).json({ error: 'invalid credentials' });
+    const token = generateToken(user.customer_no);
+    res.json({ token });
+  } catch (err) {
+    logger.error(err, 'login failed');
+    res.status(500).json({ error: 'something went wrong' });
+  }
+}
+
+module.exports = { login };

src/controllers/details.js

@@ -0,0 +1,9 @@
+const { logger } = require('../util/logger');
+const detailsObject = require('./rajatDetails_wt.json');
+
+function getDetails(user) {
+  logger.info(user);
+  return detailsObject;
+}
+
+module.exports = { getDetails };

src/controllers/rajatDetails_nt.json

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+[
+  {
+    "stAccountNo": "50067217630",
+    "stAccountType": "SA",
+    "stBookingNumber": "SAVING CHQ FOR NONME",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "SAVING CHQ FOR NONME",
+    "stApprovedAmount": null,
+    "stAvailableBalance": "933.84",
+    "stCurrentBalance": "933.84",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077736845",
+    "stAccountType": "TD",
+    "stBookingNumber": "TD-LTD-NM-IND -1 Yrs",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "TD-LTD-NM-IND -1 Yrs",
+    "stApprovedAmount": null,
+    "stAvailableBalance": "10000.00",
+    "stCurrentBalance": "10000.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077742351",
+    "stAccountType": "LN",
+    "stBookingNumber": "DL-AGAINST DEPOSIT",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "DL-AGAINST DEPOSIT",
+    "stApprovedAmount": "10000.00",
+    "stAvailableBalance": "10236.00",
+    "stCurrentBalance": "10236.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077756089",
+    "stAccountType": "TD",
+    "stBookingNumber": "TD-LTD-NM-IND -1 Yrs",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "TD-LTD-NM-IND -1 Yrs",
+    "stApprovedAmount": null,
+    "stAvailableBalance": "10000.00",
+    "stCurrentBalance": "10000.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077842356",
+    "stAccountType": "LN",
+    "stBookingNumber": "DL-AGAINST DEPOSIT",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "DL-AGAINST DEPOSIT",
+    "stApprovedAmount": "10000.00",
+    "stAvailableBalance": "10215.00",
+    "stCurrentBalance": "10215.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50078072406",
+    "stAccountType": "LN",
+    "stBookingNumber": "TL-PERSONAL",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "TL-PERSONAL",
+    "stApprovedAmount": "200000.00",
+    "stAvailableBalance": "200825.00",
+    "stCurrentBalance": "200825.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  }
+]

src/controllers/rajatDetails_wt.json

@@ -0,0 +1,212 @@
+[
+  {
+    "stAccountNo": "50067217630",
+    "stAccountType": "SA",
+    "stBookingNumber": "SAVING CHQ FOR NONME",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "SAVING CHQ FOR NONME",
+    "stApprovedAmount": null,
+    "stAvailableBalance": "933.84",
+    "stCurrentBalance": "933.84",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "transactions": [
+      {
+        "id": "abcd",
+        "name": "John Doe",
+        "date": "31-05-2025 09:05:31",
+        "type": "CR",
+        "amount": 612
+      },
+      {
+        "id": "efgh",
+        "name": "John Cena",
+        "date": "20-05-2025 09:05:20",
+        "type": "DR",
+        "amount": 10
+      }
+    ],
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077736845",
+    "stAccountType": "TD",
+    "stBookingNumber": "TD-LTD-NM-IND -1 Yrs",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "TD-LTD-NM-IND -1 Yrs",
+    "stApprovedAmount": null,
+    "stAvailableBalance": "10000.00",
+    "stCurrentBalance": "10000.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "transactions": [
+      {
+        "id": "abcd",
+        "name": "John Doe",
+        "date": "31-05-2025 09:05:31",
+        "type": "CR",
+        "amount": 10
+      },
+      {
+        "id": "efgh",
+        "name": "John Cena",
+        "date": "20-05-2025 09:05:20",
+        "type": "DR",
+        "amount": 662
+      }
+    ],
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077742351",
+    "stAccountType": "LN",
+    "stBookingNumber": "DL-AGAINST DEPOSIT",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "DL-AGAINST DEPOSIT",
+    "stApprovedAmount": "10000.00",
+    "stAvailableBalance": "10236.00",
+    "stCurrentBalance": "10236.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "transactions": [
+      {
+        "id": "abcd",
+        "name": "John Doe",
+        "date": "31-05-2025 09:05:31",
+        "type": "CR",
+        "amount": 676
+      },
+      {
+        "id": "efgh",
+        "name": "John Cena",
+        "date": "20-05-2025 09:05:20",
+        "type": "DR",
+        "amount": 684
+      }
+    ],
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077756089",
+    "stAccountType": "TD",
+    "stBookingNumber": "TD-LTD-NM-IND -1 Yrs",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "TD-LTD-NM-IND -1 Yrs",
+    "stApprovedAmount": null,
+    "stAvailableBalance": "10000.00",
+    "stCurrentBalance": "10000.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "transactions": [
+      {
+        "id": "abcd",
+        "name": "John Doe",
+        "date": "31-05-2025 09:05:31",
+        "type": "CR",
+        "amount": 698
+      },
+      {
+        "id": "efgh",
+        "name": "John Cena",
+        "date": "20-05-2025 09:05:20",
+        "type": "DR",
+        "amount": 706
+      }
+    ],
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50077842356",
+    "stAccountType": "LN",
+    "stBookingNumber": "DL-AGAINST DEPOSIT",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "DL-AGAINST DEPOSIT",
+    "stApprovedAmount": "10000.00",
+    "stAvailableBalance": "10215.00",
+    "stCurrentBalance": "10215.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "transactions": [
+      {
+        "id": "abcd",
+        "name": "John Doe",
+        "date": "31-05-2025 09:05:31",
+        "type": "CR",
+        "amount": 721
+      },
+      {
+        "id": "efgh",
+        "name": "John Cena",
+        "date": "20-05-2025 09:05:20",
+        "type": "DR",
+        "amount": 729
+      }
+    ],
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  },
+  {
+    "stAccountNo": "50078072406",
+    "stAccountType": "LN",
+    "stBookingNumber": "TL-PERSONAL",
+    "stBranchNo": "00002 ",
+    "stCurrency": "INR",
+    "stProductType": "TL-PERSONAL",
+    "stApprovedAmount": "200000.00",
+    "stAvailableBalance": "200825.00",
+    "stCurrentBalance": "200825.00",
+    "custdob": "02051982",
+    "custname": "RAJAT MAHARANA",
+    "mobileno": "919418573848",
+    "custaddress": "DATA CENTRE KCCB CIVIL BAZAR D/SHALA DHARAMSHALA KANGRA",
+    "pincode": "176215",
+    "id": "AMSPM8798H",
+    "transactions": [
+      {
+        "id": "abcd",
+        "name": "John Doe",
+        "date": "31-05-2025 09:05:31",
+        "type": "CR",
+        "amount": 10
+      },
+      {
+        "id": "efgh",
+        "name": "John Cena",
+        "date": "20-05-2025 09:05:20",
+        "type": "DR",
+        "amount": 751
+      }
+    ],
+    "activeAccounts": 6,
+    "cifNumber": "30022497139"
+  }
+]

src/middlewares/auth.middleware.js

@@ -0,0 +1,25 @@
+const { verifyToken } = require('../util/jwt');
+const { logger } = require('../util/logger');
+
+function auth(req, res, next) {
+  const authHeader = req.headers.authorization;
+
+  if (!authHeader || !authHeader.startsWith('Bearer ')) {
+    return res
+      .status(401)
+      .json({ error: 'missing or malformed authorization header' });
+  }
+
+  const token = authHeader.split(' ')[1];
+
+  try {
+    const payload = verifyToken(token);
+    req.user = payload;
+    next();
+  } catch (err) {
+    logger.error(err, 'error verifying token');
+    return res.status(401).json({ error: 'invalid or expired token' });
+  }
+}
+
+module.exports = auth;

src/routes/auth.js

@@ -0,0 +1,8 @@
+const express = require('express');
+const { login } = require('../controllers/auth.controller');
+
+const router = express.Router();
+
+router.post('/login', login);
+
+module.exports = router;

src/routes/details.js

@@ -0,0 +1,12 @@
+const express = require('express');
+const customerController = require('../controllers/details');
+const auth = require('../middlewares/auth.middleware');
+const router = express.Router();
+
+router.get('/details', auth, (req, res) => {
+  const user = req.user;
+  const details = customerController.getDetails(user);
+  return res.json(details);
+});
+
+module.exports = router;

src/routes/index.js

@@ -0,0 +1,12 @@
+const express = require('express');
+const testRoute = require('./test');
+const authRoute = require('./auth');
+const detailsRoute = require('./details');
+
+const router = express.Router();
+
+router.use('/test', testRoute);
+router.use('/auth', authRoute);
+router.use('/customer', detailsRoute);
+
+module.exports = router;

src/routes/test.js

@@ -0,0 +1,16 @@
+const express = require('express');
+const db = require('../config/db');
+const { logger } = require('../util/logger');
+const router = express.Router();
+
+router.get('/ping-db', async (_req, res) => {
+  try {
+    const result = await db.query('SELECT NOW()');
+    res.json({ time: result.rows[0].now });
+  } catch (err) {
+    logger.error(err);
+    res.status(500).json({ error: err });
+  }
+});
+
+module.exports = router;

src/server.js

@@ -0,0 +1,22 @@
+const app = require('./app');
+const { port } = require('./config/config');
+const { logger } = require('./util/logger');
+const db = require('./config/db');
+
+const server = app.listen(port, () => {
+  logger.info(`server listening on http://localhost:${port}`);
+});
+
+const shutdown = () => {
+  logger.info('shutting down server...');
+  server.close(() => {
+    logger.info('http server closed');
+    db.pool.end(() => {
+      logger.info('pg pool has ended');
+      process.exit(0);
+    });
+  });
+};
+
+process.on('SIGINT', shutdown);
+process.on('SIGTERM', shutdown);

src/services/auth.service.js

@@ -0,0 +1,21 @@
+const db = require('../config/db');
+const { comparePassword } = require('../util/hash');
+const { logger } = require('../util/logger');
+
+async function findUserByCustomerNo(customerNo) {
+  const result = await db.query('SELECT * FROM users WHERE customer_no = $1', [
+    customerNo,
+  ]);
+  return result.rows[0];
+}
+
+async function validateUser(customerNo, password) {
+  const user = await findUserByCustomerNo(customerNo);
+  if (!user) return null;
+  logger.info(typeof user);
+  logger.info(user, 'user from database');
+  const isMatch = await comparePassword(password, user.password_hash);
+  return isMatch ? user : null;
+}
+
+module.exports = { validateUser };

src/util/hash.js

@@ -0,0 +1,17 @@
+const bcrypt = require('bcrypt');
+const { logger } = require('./logger');
+
+async function hashPassword(password) {
+  return await bcrypt.hash(password, 10);
+}
+
+async function comparePassword(plain, hash) {
+  const hashedPassword = await hashPassword(plain);
+  logger.info(hashedPassword, 'passed password after hashing');
+  return await bcrypt.compare(plain, hash);
+}
+
+module.exports = {
+  hashPassword,
+  comparePassword,
+};

src/util/jwt.js

@@ -0,0 +1,15 @@
+const jwt = require('jsonwebtoken');
+const { jwtSecret } = require('../config/config');
+
+function generateToken(payload, expiresIn = '1h') {
+  return jwt.sign({ payload }, jwtSecret, { expiresIn });
+}
+
+function verifyToken(token) {
+  return jwt.verify(token, jwtSecret);
+}
+
+module.exports = {
+  generateToken,
+  verifyToken,
+};

src/util/logger.js

@@ -0,0 +1,22 @@
+const pino = require('pino');
+const isDev = process.env.NODE_ENV !== 'production';
+
+const logger = pino({
+  transport: isDev
+    ? {
+        target: 'pino-pretty',
+        options: {
+          colorize: true,
+          translateTime: 'SYS:standard',
+          ignore: 'pid,hostname',
+        },
+      }
+    : undefined,
+  level: isDev ? 'debug' : 'info',
+});
+
+const requestLogger = (req, _res, next) => {
+  logger.info(`${req.method} ${req.url}`);
+  next();
+};
+module.exports = { logger, requestLogger };