MERN Authentication Tutorial #4 - Email & Password Validation

all right then so in this lesson what i'd like to do is implement on the server a bit of logic to validate these two values the email and the password before we try to sign the user up so that if the value that a user tries to use for the email isn't a valid email we can send an error back and also if the password is maybe not strong enough we can send an error back as well so let me just show you what happens at the minute if we try to just save something like yoshi and also a password of just a now this is not an email and this is not really a strong password if we try to send this then we still get back a 200 response and we've saved that user to the database even though that's not an email and the password is rubbish so we don't want to do that and also if i try to send something with a blank password and a blank email as well if i send that then we can see this error right here now this is not a great error response i wouldn't output this at the bottom of a form so i want to make a better error for something like that as well so we need to check that these values actually exist as well before we try to save them so where do we want to put all of this validation logic well there's a couple of different places we could do this we could do it directly in the signup user controller function right here but what i'd like to do instead is keep all of the signup logic together including these validation checks and put it inside this sign up static method right here all right so the first thing i'm going to do is actually install a package called validator and that's instead of me coming up with a lot of regex to check against the email and the password it's going to do that for me so let's install that package by cancelling out of this process down here and then typing npm install validator like so all right and when that's installed we need to come up here and we need to require that so const validator is equal to require and we want to require the validator package all right so down here where do we want to do this validation well really we want to do it before we try any of this down here because if none of the fields are valid or if one of them is not valid we don't need to do the rest of this stuff we just send back some kind of error so let's do a comment that says validation and then below that first of all i want to make sure that we actually have a value for the email and the password so we'll do a little lift check to say if not email and then or so double pipe not password so if we don't have a value for either of these then we're gonna throw an error and the error that we throw is gonna have the message all fields must be filled so now if we try to send the request whereby the email doesn't exist or the password or both then we're going to throw this error and obviously we catch that error down here and we respond with a json message which is the error itself so this message right here so that is ultimately what would show underneath the form on the react application so that's the first check the second thing i want to do is check if the email is a valid email and for this we're going to use our validator package so we're going to say if not validator and then dots and then we use a method called is email so this checks if something is an email and we want to pass through this email thing right here so this is going to return true or false true if it is a valid email false if it's not now if it is a valid email we reverse that to be false so therefore the if block won't fire but if it's not a valid email and this is false we reverse that using this exclamation and this is going to evaluate to true and therefore it will fire so we can throw an error if it's not a valid email so we can say throw error and the message this time is going to be email is not valid all right and there's one more we want to do and that is to check if the password is strong enough so i'm going to say if not again validator and then we use a method called is strong password all right so this is something like if the password has uppercase lowercase and a symbol or something like that and maybe a minimum length of eight maybe more i don't know but we'll find out soon enough anyway we pass in the password this thing right here into that and then therefore if the password is not strong enough we throw an error again this time we'll just say password not strong enough like so spell this correctly all right and that is pretty much all of the validation we really need to do here we're checking that the fields have values then that we have a valid email and then that the password is strong enough and obviously down here we do another check to make sure that email hasn't already been used all right so now this is all done let's try this again in postman all right then so first of all to this endpoint let's try not adding an email and a password so if we send this hopefully yeah we get that error message back all fields must be filled all right so let's also try adding an email like yoshi at netninja.dev press send and again all fields must be filled because we don't have a password all right let's say abc like so so let's send this again so now we can see the password is not strong enough so let's try capitals a b c at the start then normal abc then one two three and then an exclamation so if we send this then we see the email is already in use because we already tried to sign up with yoshi at netninja.dev so now let's try bowser and hopefully this is all going to work now and yeah we can see that document was created and we get it back right here with the hashed password so all of that kind of validation logic is in place now

Channel: Net Ninja

Views: 31,262

Keywords: MERN, MERN stack, MERN tutorial, MERN auth, MERN authentication, MERN auth tutorial, MERN authentication tutorial, MERN stack tutorial, auth, auth tutorial, authentication tutorial, jwt, jwt tutorial, json web tokens, json web tokens tutorial, node auth, node auth tutorial, jwt auth, jwt auth tutorial, express auth

Id: sRFI6L0a38E

Length: 6min 2sec (362 seconds)

Published: Thu Jul 21 2022