validation entry

validation-index.ts

import { Router, Response, Request } from "express";
import express from "express";
import bodyParser from "body-parser";

class UserDto {
    username: String;
    password: String;
    email: String;
}

const app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
const router = Router();

router.post("/user/submit", async (req: Request, res: Response) => {
    const { username, email, password } = req.body;
    const passwordReg = /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z]{8,}$/;
    const emailReg = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    let validationError = false;
    if (!username) {
        res.status(400).send("username is required");
        validationError = true;
    }
    if (!email) {
        res.status(400).send("email is required");
        validationError = true;
    }
    if (!password) {
        res.status(400).send("password is required");
        validationError = true;
    }
    if (!passwordReg.test(password)) {
        res.status(400).send("password should contains at least one upper char, one lower char, one digit and 8 characters");
        validationError = true;
    }
    if (!emailReg.test(email)) {
        res.status(400).send("email is not valid");
        validationError = true;
    }
    if (!validationError) {
        const user = new UserDto();
        user.username = username;
        user.password = password;
        user.email = email;
        // pass 'user' object to repository/service 
        res.json({ username, email, password });
    }
});
app.use(router);
app.listen(3000, () => {
    console.log('Server is running in http://localhost:3000');
});