I got error while validating field in mongodb, nodejs - node.js

Question

These are the errors I got from backend while validating in model and received in 'err' variable. If I console.log(err), then it shows following errors.
Error [ValidationError]: employees validation failed: fullName: This field is required from model, email: This field is required from model
at ValidationError.inspect (D:\Programming\MERN\CRUD\node_modules\mongoose\lib\error\validation.js:61:24)
at formatValue (internal/util/inspect.js:703:31)
at inspect (internal/util/inspect.js:272:10)
at formatWithOptions (internal/util/inspect.js:1887:40)
at Object.Console.<computed> (internal/console/constructor.js:284:10)
at Object.log (internal/console/constructor.js:294:61)
at handleValidationError (D:\Programming\MERN\CRUD\routes\/employeeRoute.js:46:13)
at D:\Programming\MERN\CRUD\routes\/employeeRoute.js:33:17
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\model.js:4915:16
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\helpers\promiseOrCallback.js:16:11
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\model.js:4938:21
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\model.js:492:16
at D:\Programming\MERN\CRUD\node_modules\kareem\index.js:246:48
at next (D:\Programming\MERN\CRUD\node_modules\kareem\index.js:167:27)
at next (D:\Programming\MERN\CRUD\node_modules\kareem\index.js:169:9)
at Kareem.execPost (D:\Programming\MERN\CRUD\node_modules\kareem\index.js:217:3) {
errors: {
fullName: MongooseError [ValidatorError]: This field is required from model
at new ValidatorError (D:\Programming\MERN\CRUD\node_modules\mongoose\lib\error\validator.js:29:11)
at validate (D:\Programming\MERN\CRUD\node_modules\mongoose\lib\schematype.js:1178:13)
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\schematype.js:1161:7
at Array.forEach (<anonymous>)
at SchemaString.SchemaType.doValidate (D:\Programming\MERN\CRUD\node_modules\mongoose\lib\schematype.js:1106:14)
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\document.js:2378:18
at processTicksAndRejections (internal/process/task_queues.js:79:11) {
properties: [Object],
kind: 'required',
path: 'fullName',
value: '',
reason: undefined,
[Symbol(mongoose:validatorError)]: true
},
email: MongooseError [ValidatorError]: This field is required from model
at new ValidatorError (D:\Programming\MERN\CRUD\node_modules\mongoose\lib\error\validator.js:29:11)
at validate (D:\Programming\MERN\CRUD\node_modules\mongoose\lib\schematype.js:1178:13)
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\schematype.js:1161:7
at Array.forEach (<anonymous>)
at SchemaString.SchemaType.doValidate (D:\Programming\MERN\CRUD\node_modules\mongoose\lib\schematype.js:1106:14)
at D:\Programming\MERN\CRUD\node_modules\mongoose\lib\document.js:2378:18
at processTicksAndRejections (internal/process/task_queues.js:79:11) {
properties: [Object],
kind: 'required',
path: 'email',
value: '',
reason: undefined,
[Symbol(mongoose:validatorError)]: true
}
},
_message: 'employees validation failed'
}
Now if I console.log('err.errors.fullName.message'). It works perfectly.
But if there are more keys, it's obvious that we need to use loop. So if I try to iterate through keys of object as follow, then it throws following error.
for(field in err.errors){
.......
.......
}
Error is:
ReferenceError: field is not defined
What's the problem here ?

Answer 1

First of all your backend should not give this type of error response as you mentioned in the above. This must be like a JSON response of errors. e.g
{ success: false, errors: [{fullName: "fullName is required"}] }
Coming to your question. If you want to show error properly you can loop through the error which you can pic by the err.errors
eg err.errors.forEach(error => console.log(error) )
But again this is a very wrong way to throw the validation error. To validate any data you can use joi, request-validator, validatorjs, etc. Which will give you a perfect error response as you want? Why I am giving stress on this because you are exposing entire directory, files, model name, etc.
I hope this may help you to solve your problem