How do you handle mongodb ObjectId ?

[balazssoltesz]

Hello,

im trying to use express-openapi-validator with mongodb, but I can't figure out how should I handle ObjectId fields.
I have to specify id fields in the openapi.json as string, and in res.json() it will be converted to string as well, but if i set validateResponses to true then it will throw an error for me (id should be string).
Any idea how to handle properly mongodb _id fields?

[cdimascio]

You will want to send _id as a string. If you are returning the objectid as is, it's likely to be object and not a string, hence why the validator complains that it should be a string.

[balazssoltesz]

Yes I understand but practically it will be sent as string cause res.json() convert it to string. Should I iterate over the whole collection to convert any ObjectId field to string manually to avoid validation error?

[balazssoltesz]

maybe if i could map custom types to custom formats could solve this problem. Then i could map "string | ObjectId" type to "ObjectId" custom format.

[pilerou]

I managed objectid as described here
#353

[pilerou]

@cdimascio it could be great to add it. If you want I could try to push for a merge request

[cdimascio]

hey all @pilerou has propsed a solution #493
please have a look. feedback is greatly appreciated

[cdimascio]

@balazssoltesz this is now resolved by using the serDes option. See serDes doc.

@pilerou has also provided a serializer/deserializer lib that can be used with the validator to handle mongodb object.

See the readme for details on both