Mongoose: ObjectId Comparisons fail inconsistently

Question

I have a straightforward tool for building collections of documents and then automatically formatting them for EPUB or LaTeX rendering, written on top of ExpressJS. I\'m us

Answer 1

This goes somewhat beyond the original asked question, but I have found that the .equals method of ObjectID's will return false in some cases where a string comparison will return true even when the values are not null. Example:

var compare1 = invitationOwningUser.toString() === linkedOwningUser.toString();
var compare2 = invitationOwningUser.equals(linkedOwningUser);
var compare3 = String(invitationOwningUser) === String(linkedOwningUser);
logger.debug("compare1: " + compare1 + "; " + "compare2: " + compare2 + "; " + "compare3: " + compare3);

Output:

compare1: true; compare2: false; compare3: true 

This occurred when invitationOwningUser (an ObjectID) came from a Collection created using a Mongoose schema, and linkedOwningUser (also an ObjectID) came from a Collection not created using Mongoose (just regular MongoDB methods).

Here is the document containing invitationOwningUser (the owningUser field):

{
    "_id" : ObjectId("5782faec1f3b568d58d09518"),
    "owningUser" : ObjectId("5781a5685a06e69b158763ea"),
    "capabilities" : [
        "Read",
        "Update"
    ],
    "redeemed" : true,
    "expiry" : ISODate("2016-07-12T01:45:18.017Z"),
    "__v" : 0
}

Here is the document containing linkedOwningUser (the owningUser field):

{
    "_id" : ObjectId("05fb8257c95d538d58be7a89"),
    "linked" : [
        {
            "owningUser" : ObjectId("5781a5685a06e69b158763ea"),
            "capabilities" : [
                "Read",
                "Update"
            ]
        }
    ]
}

So, as a bottom line for me, I'll be using the string comparison technique to compare ObjectID's, not the .equals method.