What is the best approach for validating inputs on the backend?

Question

What is the best approach for validating inputs on the backend?

My web app will be receiving a significant amount of user-generated content. To enhance basic security measures, I aim to validate the inputs created by users. Currently, my backend is powered by Node+Express.

How should I go about implementing input validation?

Should I use assert? Being familiar with Python, my initial instinct was to utilize assert statements: assert(title.length > 0)
Or perhaps express-validator? Upon further research, I came across form validation libraries like express-validator which seemed like a more structured approach. However, it also appeared that this method would require me to write significantly more lines of code compared to simple assertion statements.
Could TypeScript be the solution? I then considered the option of writing some of my Node code in TypeScript as a potential solution to handle all validations automatically.
What other options are available?

Which approach would be most suitable for my project?

node.js typescript express express-validator

Answer 1

Answer №1

To prevent cross-site scripting (XSS) attacks, it is crucial to sanitize user input properly. Fortunately, there are numerous NPM packages available for this task, such as DOMPurify which does an excellent job.

One simple way to validate input is by using conditional if statements, like the example below:

app.post("/user", (req, res) => {
    const { email, password } = req.body;
    if (!email || !validator.isEmail(email)) {
        return res.status(400).send("Invalid email");
    } else if (!password || password.length < 8) {
        return res.status(400).send("Invalid password");
    }
    // Do stuff
    return res.sendStatus(200);
});

Validation libraries can be very helpful in this process, like using the isEmail function from the validator library in the above example.

It's important to note that TypeScript does not perform runtime validation; it conducts type-checking during compilation and converts TypeScript code into JavaScript without types, meaning errors may not be thrown if a field's type mismatches at runtime.

Validating each input in every request might get tedious and messy, but you can simplify this process by implementing Express middlewares that can easily be added to specific requests requiring validation.

Answer 2

To prevent cross-site scripting (XSS) attacks, it is crucial to sanitize user input properly. Fortunately, there are numerous NPM packages available for this task, such as DOMPurify which does an excellent job.

One simple way to validate input is by using conditional if statements, like the example below:

app.post("/user", (req, res) => {
    const { email, password } = req.body;
    if (!email || !validator.isEmail(email)) {
        return res.status(400).send("Invalid email");
    } else if (!password || password.length < 8) {
        return res.status(400).send("Invalid password");
    }
    // Do stuff
    return res.sendStatus(200);
});

Validation libraries can be very helpful in this process, like using the isEmail function from the validator library in the above example.

It's important to note that TypeScript does not perform runtime validation; it conducts type-checking during compilation and converts TypeScript code into JavaScript without types, meaning errors may not be thrown if a field's type mismatches at runtime.

Validating each input in every request might get tedious and messy, but you can simplify this process by implementing Express middlewares that can easily be added to specific requests requiring validation.

What is the best approach for validating inputs on the backend?

Answer №1

Similar questions

Finding the external port of the http request within an expressjs context

Is Node.js truly a single-threaded and non-blocking platform?

Installing Global Node Packages in the Incorrect Directory

TypeScript encounters difficulty resolving an exported default class

Understanding the variance between using app.get() and router.get() in the ExpressJs framework

The assets folder is experiencing difficulties loading files on sub pages

How to Implement an Asynchronous Function in Node.js

Show every item from a collection on individual lines within an Angular2 module

Is it possible to combine JavaScript objects using TypeScript?

Defining the NgRx root state key within the application state interface

What could be the reason behind the for loop not running within a typescript function?

Generic function's contravariance predicament

I'm looking for a way to fetch data from MySQL using React Native when a button is clicked

The type 'FormikValues' is deficient in the subsequent properties compared to the type 'Exact<{'

Having trouble with a particular npm package not functioning properly in node.js? Encountering an issue with the error message "perl rules/compile-rules.pl 'perl' is not recognized as an internal or external

What could be causing the error "Unexpected identifier 'trytoCatch' while trying to minify?

We regret to inform you that an unexpected runtime error has occurred: TypeError - require.e is

Invalid JWT format: The object on the right side of the 'instanceof' operator is not recognized as an object

The Freemode feature in SwiperJS is not functioning properly when used with React TypeScript

Tips for distinguishing genuine meta preview requests from bots when using a URL shortener?