How to change response code and data

[supasate]

I would like my API to return 404 Not Found when a requested data does not exist. Currently, it responds with 400 Bad Request. How can I intercept and modify the response?

Example
Request: GET localhost/mymodels/1234
Response header: 400 Bad Request
Response Data: {"name":"BadRequest","message":"Cast to ObjectId failed for value \"1234\" at path \"_id\"","code":400,"className":"bad-request","errors":{}}

I would like to change the response to something like this:

Response header: 404 Not Found
Response data: {"name":"NotFound","message":"Requested ID does not exist","code":404,"className":"not-found","errors":{}}

or just

Response Header: 404 Not Found
Response data: {"name":"NotFound","message":"Requested ID does not exist","code":404}

[marshallswain]

Can you try throwing an error using one of the feathers-errors?

[supasate]

Sound like I have to intercept the error from feathers-mongoose for the GET request and check that error if it's the Cast to ObjectId Failed. Then, throw my modified error with feathers-errors out.

But, I'm not quite sure where should I intercept and throw the error. Please advise.

Here's my code.

const service = require('feathers-mongoose');

module.exports = function() {
  const app = this;
  const options = {
    Model: mymodels,
    paginate: {
      default: 5,
      max: 50
    }
  };
  app.use('/mymodels', service(options));
}

[daffl]

Not having a 404 here should definitely be fixed in the adapter. To further customize the errors I am thinking of adding afterError hooks but for now you can probably extend the adapter and throw your own errors.

[supasate]

I found the root cause is caused by using Mongoose findOne with id. So, when a requested id is not in the proper ObjectId format, Mongoose throws CastError.

Should we fix it by first checking the format? If it's not in ObjectId format, we throw new errors.NotFound(No record found for id '${id}') instead.

If you think it's ok to fix this way, I would like to try to send a PR to fix it.

[supasate]

@daffl I created a PR on this issue. I'm new to this community. Please advise.

[ekryski]

I don't think this should actually throw a 404, because if it is a bad ID (which it is) then it actually is a bad request. If you want to have a 404 you can easily add your own before hook to quickly check if hook.id is a valid ObjectId and if not throw a NotFound error.

[ekryski]

The other thing is we currently support having an alternative id field as the primary query id instead of the default _id so we can't just throw a 404 on any id that isn't an ObjectId. For example, you could be using something like email as your primary id to query by.

[daffl]

For the hook implementation for this case see #103 (comment)

[supasate]

@ekryski @daffl I agree. I totally forgot about alternative id. Thank you for your clarification and help.