Mongoose Subdocument will not update - node.js

Question

I am having trouble figuring out if I designed the schema correctly because I am receiving a 500 error when attempting to PATCH changes of the roles property from a profile. (Note: The 500 error just responds with an empty {}, so it isn't really informative)
Below is the profile schema:
var ProfileSchema = new Schema({
name: {
type: String,
required: true
},
roles: [{
application: {
type: Schema.Types.ObjectId,
required: true,
ref: 'Application'
},
role: {
type: String,
required: true,
enum: [ 'admin', 'author', 'publisher' ]
}
}]
});
Each profile has a role for an application, and when I send the request to the controller action 'update', it fails:
profile update controller:
// Updates an existing Profile in the DB
export function update(req, res) {
try {
if (req.body._id) {
delete req.body._id;
}
console.log('ENDPOINT HIT...');
console.log(`REQUEST PARAM ID: ${req.params.id}`);
console.log('REQUEST BODY:');
console.log(req.body);
console.log('ENTIRE REQUEST: ');
return Profile.findByIdAsync(req.params.id)
.then(handleEntityNotFound(res))
.then(saveUpdates(req.body))
.then(respondWithResult(res))
.catch(handleError(res));
} catch(ex) {
console.error('FAILED TO UPDATE PROFILE');
return handleError(res);
}
}
I made sure that the id and body was being sent properly, and I am hitting the end point.
This is an example of the request body JSON:
{
_id: 57e58ad2781fd340563e29ff,
__updated: Thu Oct 27 2016 15:41:12 GMT-0400 (EDT),
__created: Fri Sep 23 2016 16:04:34 GMT-0400 (EDT),
name: 'test',
__v: 11,
roles:[
{ application: 57b70937c4b9fe460a235375,
role: 'admin',
_id: 58125858a36bd76d8111ba16 },
{ application: 581b299f0145b48adf8f57bd,
role: 'publisher',
_id: 581b481898eefb19ed8a73ee }
]
}
When I try to find the Profile by Id, the promise chain goes straight to the catch(handleError(res)); part of the code and shows an empty object in my console.
My handle error function:
function handleError(res, statusCode) {
console.error('HANDLE PROFILE ERROR: ', statusCode);
statusCode = statusCode || 500;
return function(err) {
console.error('PROFILE ERROR:');
console.error(JSON.stringify(err, null, 2));
res.status(statusCode).send(err);
};
}
UPDATE
I am realizing the code is breaking when it hits my saveUpdates function (Note: I am using lodash):
function saveUpdates(updates) {
/// the code is fine here ///
return function(entity) {
/// once it enters in here, is where it begins to break ///
var updated = _.merge(entity, updates);
if(updated.roles.length != updates.roles.length) {
updated.roles = updates.roles;
}
for(var i in updates.roles) {
updated.roles.set(i, updates.roles[i]);
}
return updated.saveAsync()
.then(updated => {
return updated;
});
};
}

Answer 1

Lesson learned: Read Documentation properly.
Since I am using bluebird promises for this application, I forgot to use .spread() within my saveUpdates() callback function.
Solution:
function saveUpdates(updates) {
return function(entity) {
var updated = _.merge(entity, updates);
if(updated.roles.length != updates.roles.length) {
updated.roles = updates.roles;
}
for(var i in updates.roles) {
updated.roles.set(i, updates.roles[i]);
}
return updated.saveAsync()
// use `.spread()` and not `.then()` //
.spread(updated => {
return updated;
});
};
}
I want to thank the following SOA that led to this conclusion: https://stackoverflow.com/a/25799076/5994486
Also, here is the link to the bluebird documentation in case anyone was curious on .spread(): http://bluebirdjs.com/docs/api/spread.html