typs

An handy library for type validation in Javascript

Just

npm install typs --save

it.

The library is still widely open to changes, so feel free to propose new features or open an issue.

What can I use it for?

Param checking

Write a sound REST API or provide strong code constraints validating your parameters

app.get('/api/v1/users/:user_id', (req) => {
    var user_id = req.params.user_id;
    if(typs(user_id).integer().positive().notZero()) {
        throw new Error('user_id is not a valid identifier');
    }
    // ...
});

Input validation

Let typs handle your validation logic in an easy and semantic way

const usernameType = typs().string().notEmpty().len({min: 5, max: 15});
const uniqueUsernameType = usernameType.satisifies((username) =>
    // yes, typs supports promises!
    query('SELECT * FROM users WHERE username = ?', username)
        .then((rows) => rows.length < 1);
);
const passwordType = typs().string().notEmpty().len({min: 8, max: 25});
const emailType = typs().string().notEmpty().regex(/* ...a long mail regex... */);
 
function add_user(username, password, email) {
    if(typs(username).isnt(usernameType)) {
        throw new Error('the username you provided is not a valid username')
    }
    if(typs(password).isnt(passwordType)) {
        throw new Error('the password you provided is not valid');
    }
    if(typs(email).isnt(emailType)) {
        throw new Error('the e-mail you provided is not valid');
    }
 
    typs(username).isnt(uniqueUsernameType).then((pass) => {
        if (!pass) throw new Error('this username already exists, please pick another');
        // ...
    });
}

License

Typs comes with a good, ol' MIT license.