Node Auth Tutorial (JWT) #5 - Mongoose Validation

all right then gang so we saw in the last video that currently when we send incorrect data with our post request we get back a blanket error that looks something like this no matter what the error is whether that's an empty email property or the password is too short etc now that wouldn't be great to show a user on a web page because it doesn't offer any additional info so they won't know what to correct instead it would be good to create custom error messages for different types of errors and we'll be using a combination of custom error handling and mongoose validation errors to do this so back in the code we can first come to our mongoose user over here and we can add some custom error messages for the different conditions that we specified like this required so the way we do that is by surrounding this inside an array now the first value of the array is the actual value of this is it required well yes so this is true now we can pass in a second value into the array and that is a custom error message for if this fails so if they don't supply an email then we can trigger an error message which says this thing right here so all i'm going to say right here is please enter an email now i'm going to do the same thing for requires down on the password over here but this time i'm going to change this to password right now i also want to do the same thing for min length so let me surround this in square brackets and again the first position is going to be the value of the min length and then the second position is going to be the error message so i'm going to say minimum password length is six characters right so these are the error messages that we're going to basically throw if these conditions aren't matched when a user tries to submit the form and we try to create the user right now we also need for the email an extra property right here called validate now the reason i'm doing this is because we want our email to be a valid email address at the minute they could just type in any string like a name and there's nothing here that says otherwise so i could just type in mario and well it's a string it's there we've typed something in it's unique it's not in the database and we've turned it to lowercase but there's nothing saying it has to be an email so we can add this validate property to any different field inside our schema and this is going to be an array again the first position in this is going to be a function so i could create a function right here which does something in here some custom validation now inside this function we automatically take in a value and that value is the value of the user email that is submitted to whatever the user types when we click submit so we take that value and we can validate it inside this function now we'd return true if we think it's valid and it passes we return false if we think it's not valid and in that case we would throw an error with this error message the second position in the array so i could say please enter a valid email so inside this function you would want to do something to validate that email so to do this we could use a regular expression for email and match it against what a user submits but also we could just use a third-party validation package which is what i'll do so this package is called validator and i'm going to install it first of all so we need to create a new console and i'm going to say npm install validator now if you've got an old version of node and npm then you need to pass in the save flag like so to save it to your dependencies i've got a newer version so i don't need to do that and it's automatically going to register it inside my dependencies right here okay so now we have that installed the next thing to do is import something from that package at the top over here so this package has different functions inside it that we can use to validate different things and one of those things is to validate an email so i want to import that function to validate an email from the validator package so i'm going to say const and d structure to get the is email function so this is coming from the validator package we just installed so all we need to do down here now is instead of creating our own function just passing is email like so now this triggers a function and it automatically passes that value into it that a user submits for the email and then this looks at that value and it returns true if it is a valid email false if it's not a valid email okay so that's pretty much it for our custom errors right here we will come back to this one later on because we're going to handle that slightly differently but for now this will do now before we go any further i have just noticed an error right here this min length property should not be camelcase and this l should not be a capital letter make sure that is a lowercase otherwise this won't work okay so now we have all of these different validation messages but at the moment they are not really doing anything if we were to send a request with invalid data we would still get back this blanket error message as we can see right here and that's because in the auth controller we're sending that right here so we're kind of ignoring this error object that we catch and that error object contains this kind of information on it so what we really want to do is evaluate this error object to see what kind of error is and then send back to the user something more useful like one of these messages or if there's several errors for example an error for the email and an error for the password send back both of those messages so ultimately i'd like to send back an object right here a json object instead of just a string and that json object will contain a password property and an email property now the password property will hold the password error if there is one or a blank string or an empty string if there's not an error and the email property will contain the email error if there is one so all of this evaluating of this error object right here should probably be done in a separate function so we're not bloating our code right here and duplicating code later on when we do a similar thing down here so let us now create a function at the top of this file to handle these errors so handle errors and we'll create a const called handle errors and that is going to take in the error object that we catch down in the try catch block right here so what we can do now is just call that function handle errors and pass in the error object so up here this is where we're going to evaluate the error object and return a more useful object which we can then send back as json to the user now to begin with all i'm going to do is log to the console the error message now the message property comes on all of the errors that we get and it contains information about what type of error this is now i'm also going to log out something else and that is the error code now this code property doesn't exist on most of the areas that we're going to get but it does exist on one specific error that we're going to handle in the future in particular that is the unique error but we'll come to that later on most of the time this will be undefined but later we will need it okay so let's just take a look at this error message when we send some invalid data so let me first of all go over here and press send and then if we go back to the code we should see down in the console if we open up the other terminal this thing right here so this is the error message and it contains user validation failed and then it says please enter an email and also please enter a password this right here this is the error code like i said undefined for the most part okay so this is if we don't enter an email and if we don't enter a password but what if we enter in something like mario which is not a valid email and also just one two three which isn't at least six characters long so this should still fail on two accounts right because inside the model it must be a valid email and it must be at least six characters long so let me send this request and over here we can see again user validation failed so this is the same in both instances and this time it says please enter a valid email not please enter an email and it says the minimum password length is six characters again the code is undefined so the common thing here is this string right here user validation failed so anytime there's any kind of error which is dictated by any one of these fields right here required validate required and min length then the error message that we get is going to contain this thing right here so we can look for the presence of this in the error message in order to handle these kind of errors in a particular way so let's do that down here the first thing i'm actually going to do is create an errors object so errors is equal to an object and inside here we'll have an email property which will be an empty string to begin with and a password property which will be an empty string to begin with as well now eventually this is the thing that will be sent as json back to the user so if there's an email error we'll update this property if there's a password error we'll update this property we're going to return that at the end of this function so that down here we can store it in a constant by saying const errors is equal to whatever this function returns and then we can send that as a response right here as json right so this is what we need to populate now dependent on the errors so let's look for the presence of this user validation failed inside this error message first of all so first of all i'll do a little comment to say validation errors i like that and then i'm going to say if and we're going to take a look at the error message and we're going to see if that includes a certain phrase and that phrase is going to be this thing right here so let me grab that copy it and paste it in here and now if this is the case then we can do something with that error now all i'm going to do for now is log that to the console console.log the error just so that we can see it so if i save this now and try to send a request like this with invalid data so send that and both fields are invalid right let's take a look at this object now it is quite messy to see right here in the console it's not a great way of looking at them but hopefully we will see this in a second so this is the error object right here so first of all we get the error message at the top right this is the thing where it says user validation failed please enter an email please make sure the minimum password length is six characters etc now down here we can actually see inside the error object we have another property called errors so inside this object we have the different errors that is created by this request now there should be two of them because this validation will fail and this will fail as well so inside this error object or errors object rather there should be two properties one for email and one for password so if we scroll down a little bit we can see right here the first one email right so we can see there's a validator error please enter a valid email and down here on this email object as well we see other things we have a properties property and we'll need that in a second we also have the path and the path basically says what property that we're failing on so the email in this case uh the value which is what i use entered etc so that's the first object inside the errors object okay so the second one is the password because we had an error for the password as well and that's a minimum length error so again down here we have the properties which we'll need in a second we'll take a look at that in a minute and we also have the kind of error well it's a min length error the path so what field failed and that was the password one and the value that a user tried to create and that was one two three right so ultimately remember the end game here is to populate this with an email error and a password error if there are them okay so really what we want to do is access inside this error object right here the errors property this thing right here this errors property contains the errors it's got two keys in it email and password and both of those then contain information about those individual errors so we need to take this errors property right here and we want to get the values of each one of these things inside it we don't necessarily need the key we want the values of each key inside it so how can we get those well what we can do is we can use object.values and then pass in this errors object and that gets us the values of both of the different fields inside it so this value with the properties the kind the path and also this value from the password so let me just do that first of all let me log those to the console console.log and we want the error overall object then we want the errors object inside that which is this thing right here and then we want the values of those properties so the way we do that is by saying object dot values and then surrounding this okay so it takes this object right here this errors object and it gets us the values of the different things inside that object so not the keys but the values so if i log that to the console now if i save it and just quickly this must be a capital o otherwise this won't work so save that again and now let's try sending a request and if we go back we should be able to see these different values so we can see we have these different objects right here so let me just show you we have this array and the first one the first object is right here with the different properties and other information and remember these properties are ultimately what we want to get because they contain the message that we write and also the path to say what property we need to update and the second one down here is for the password so we have again the properties with the message inside it and the path etc okay so we want those ultimately but now we have an array of the values so what we could do is we could actually cycle through that array of values right here and then for each one of them extract the information that we need and update these different properties so let me now say for each on these so we can do that remember because this is an array and for each one we'll take in the individual error and inside here i'm going to just console.log the error and i'm going to log the properties property on each one of them all right so error dot properties like so so let me save that again and come and try to send a request that's not valid again and if we come back over here now if we scroll down we should have two objects right here we have this one and we have this one so this is ultimately what we need so for each one of these now we can say okay well the path is email so this is an email error so i'll take this property right here and we're going to update that and i'll set the message or the value of that property to be this thing right here and i can do the same for this one as well i'll say well okay this time the path is password so i'll update the password property and i'm going to set the value of that equal to this thing okay so what i could do is instead of passing in the error right here i could destructure and get the properties from the error like that and to do that i need to place this in parentheses so now all we're doing is destructuring the properties property from the error and now we have access to that without saying error.properties this does exactly the same thing and i can demo that by sending a request again and over here we get the two same values so these are the properties objects right okay so we have those now what is the next step well all i want to do now is access the errors that i have right here or the error object rather and then i need to decide which property i want to update well to do that i can pass in a string inside square brackets so for example i could say email right here and set that equal to some value and that would take this property right here the email based on this and it would update it with this value now instead of passing through email i can get that from the properties path property right here so i'm going to say properties dot path so that's either going to be email or password right so it's going to take whatever property that is and update it with something now i want to update it with the message so i can say properties dot message like so and that's all there is to it now we're updating this error object right here and in fact i'm going to call this errors instead of error makes more sense because there could be more than one so update it here and here so we're updating those with the different messages we have and if there's only one of these then we're just going to cycle through the one of them and update that particular property the other one will remain blank meaning there's no error all right now at the end of all of this we want to return the errors object that we have right here so let's do that so i'm going to save this now and if we scroll down then we're getting those errors right here because we're returning them from this function and now we can send back some json instead of just some text so dot json and inside we want to send back some json and that is basically going to be the errors that we have okay so that's all there is to it we're sending now this thing up here back to the user in json format after we've populated the different values so let's try this and come over here so we need to send a new request now and hopefully we should see an error for this and an error for this so send and we see please enter a valid email and minimum password length is six characters so let's do an email so at google.com and press send and that value goes away that error but we still have this one so let's do test123 instead and press send and hopefully yep this works and we get the user back that mongodb creates for us okay so there's one more error that we need to handle and that is to do with whether an email is unique so if i try to do this again and click send then i'm going to get some errors right here but this time we don't have any information here so we don't really know what the error is now the error is that this has to be unique remember we specified that inside the user controller over here where we said unique is true now unfortunately we can't do a custom message over here for an error like the other ones over here we can't do that with unique instead what we have to do is look for information about this error over here and that information is the error code so notice when i sent this request over here we get this error code right here and it says duplicate key error so basically this is saying that this email that you're trying to sign up with should be unique and this email already exists in the database and if we take a look inside the database if i scoot this down and go to mongodb i'm going to refresh over here we should now see mario at google.com as a user so it won't create that again and that's a good thing but we do need to update the error for this so we can look for this code and we can react to that and send back a custom error based on that so let's do that now i'm going to say duplicate error code and underneath this i'm going to say if error.code is triple equal to 1 1 0 0 0 so that's this thing over here then we're going to do something so the thing we want to do is update this property so i'll say errors dot email is equal to some kind of string and i'll say that email is already registered all right so at this point we can just return the errors like so there's no need to go any further and check these errors as well because we already have this whopping error and we can tell that to the user so we're returning errors here if this is the case otherwise we return them at the bottom after we've done all of this jazz are right here so let's save this and see if this works so if i go back over to oops i need postman so if i try to request this again send it should say that email is already registered all right then cool so now we've sorted all of our errors out by using this error handler function at the top right here now this bit right here i know was a little kind of long-winded and a little bit complex but it's just a way to create custom messages there are other ways to handle errors as well and you might have your own preferred way this is just one way by cycling through the values of the errors finding the message for each one and updating an errors object with that message right here so we have all of these errors sorted out now eventually we will show all of the errors on the web form after a user submits it whether that be the login form or the signup form and we will create those forms eventually but next up before we create the forms i want to show you first of all how to hash passwords and for that we're going to be using mongoose hooks because we never really want to store plain text passwords over here in the database that is a bad bad idea in case your database is compromised and all of your passwords are then on show so we'll be hashing those passwords first of all and we'll see how to do that or how to start that process at least in the next video using mongoose hooks

Channel: The Net Ninja

Views: 27,449

Keywords: node auth, node, node js auth, authentication, node.js auth, node authentication, node.js, tutorial, node auth tutorial, authentication tutorial, jwt, node jwt, jwt vs session, jwt auth, jwt tutorial, node jwt auth

Id: nukNITdis9g

Length: 23min 15sec (1395 seconds)

Published: Fri Aug 14 2020