As I develop a REST API, it is crucial for me to ensure the uniqueness of usernames and email addresses for every user. I have meticulously set up my database models to contain the necessary properties for this purpose. However, when it comes to route logic, I need to verify whether the provided username or email address is both valid and distinct. To achieve this validation process, I utilize the following block of code:
const existingUser = await User.findOne({
$or: [
{ username: reqData.username },
{ email: reqData.email }
]
});
if(existingUser) {
let errorMessage = '';
if(existingUser.username === reqData.username) {
errorMessage = 'This username is already taken.';
} else if(existingUser.email === reqData.email) {
errorMessage = 'This e-mail address is already associated with an account.'
} else {
errorMessage = 'The provided username or e-mail address is already in use.'
}
return res
.status(400)
.json({
message: errorMessage
});
}
What are your thoughts on the effectiveness of this code? How would you approach designing this validation logic?
On a related note: I am contemplating adding another property like "result" that indicates whether the operation was successful. Do you believe it is best practice to structure the JSON response in the following manner:
return res
.status(400)
.json({
message: errorMessage,
result: false
});