Identifying Mongoose schema validation errors as HTTP status codes - keystonejs

Question

I'm leveraging Keystone.js to provide a lightweight CMS and API. I'm checking for duplicate entries on a List as such:
Registration.schema.post('save', function(error, registration, next) {
if (error && error.name === 'MongoError' && error.code === 11000) {
error = Error(`409|${ registration['email'] } is already registered`);
}
next(error);
});
I'm parsing the status code off the error message to return in my API endpoint.
Is there a different way to provide a friendly error message for duplicates in Keystone admin and be able to return the correct status code for API calls?

Answer 1

as db version v3.6.9
$ mongod --version
db version v3.6.9
git version: 167861a164723168adfaaa866f310cb94010428f
OpenSSL version: OpenSSL 1.0.1t 3 May 2016
allocator: tcmalloc
modules: none
build environment:
distmod: debian81
distarch: x86_64
target_arch: x86_64
I think you should check for ValidationError property instead MongoError as below:
RegistrationSchema.create(obj)
.then(...)
.catch(err => console.error('[registration] output: ', err);
We'll suppose the email is not mentioned before to simulate an is required error.
You'll see like that:
[registration] error: { ValidationError: Registration validation failed: email: Path `email` is required.
at ValidationError.inspect (....)
errors:
{
email:
{ Path `email` is required.
...
message: 'Path `email` is required.',
name: 'ValidatorError',
properties: [Object],
kind: 'required',
path: 'email',
value: [],
reason: undefined,
'$isValidatorError': true } },
_message: 'Registration validation failed',
name: 'ValidationError' }