How can I print a property value in the error object?

Question

I'm making a simple user register web app. I'm using MongoDB and Express JS to register new users and save them in the database.

I've put a few validation properties in the schema, whenever a user fills invalid data that doesn't follow the schema, a validation error will be displayed in the console.

Now, what I'm trying to do is that the validation error that is written in the console has two properties that I want, which are "path" and "kind", so I can display these two in the browser for the user to see.

How can I get just the "path" and the "kind" properties out of the error object? I don't want the whole error message printed, I just want these two properties.

I tried using console.log(err.path) and console.log(err.kind), but they both return undefined.

I couldn't figure out how to access those two properties.

// Post new user (REGISTER):
router.post('/signup', async (req, res) => {

    const username = req.body.username;
    const email = req.body.email;
    const password = req.body.password;

    try {
        await User.create({username, email, password})
    } 

    catch(err) {

// I don't want the whole err, I just want err.path and err.kind if possible!
        console.log(err);
    }

});

Answer 1

The following should work. These properties are within a nested object, held by keyword errors

console.log(err.errors.username.kind, err.errors.username.path)