Meteor.js : How to run check() when arguments are Mongodb ObjectId's?

Question

In some of my Meteor methods, I'm sending Mongodb ObjectId's from the client as arguments. I'd like to run these through Meteor's check() system but I can't seem to find anything that matches successfully with them.

I've tried

var someObjectId = Meteor.Collection.ObjectId();

check(someObjectId, Meteor.Collection.ObjectId()) // fails
check(someObjectId, { _str : String }) //fails
check(someObjectId, String) //fails

any help much appreciated !

Answer 1

Instead of:

check(someObjectId, Meteor.Collection.ObjectID());

Try without the parentheses:

check(someObjectId, Meteor.Collection.ObjectID);

Edit-

Note that the error message for this check isn't ideal.

check({}, Meteor.Collection.ObjectID);
// Error: Match error: Expected

You could assume the message should be something like

// Error: Match error: Expected ObjectId, got object

You can see why this happens in this snippet from the check package.

https://github.com/meteor/meteor/blob/devel/packages/check/match.js

if (pattern instanceof Function) {
    if (value instanceof pattern)
        return;
    // XXX what if .name isn't defined
    throw new Match.Error("Expected " + pattern.name);
}

Meteor.Collection.ObjectID does not have name property.

Answer 2

As an alternative solution, you could simply pass the hexadecimal string as an argument instead of the ObjectID.

var idValidator = Match.Where(function (id) {
    check(id, String);
    return /[0-9a-fA-F]{24}/.test(id);
});

check(new Meteor.Collection.ObjectID()._str, idValidator);
// success

check('', idValidator);
// Error: Match error: Failed Match.Where validation

check({}, idValidator);
// Error: Match error: Expected string, got object

check([], idValidator);
// Error: Match error: Expected string, got object <--- bug? I expect array

Note, this regular expression is pulled from here.

https://github.com/mongodb/js-bson/blob/master/lib/bson/objectid.js

Answer 3

You should use following to generate a random ObjectID:

var someObjectId = new Meteor.Collection.ObjectID();

As Cuberto said, you can then check it by Meteor.Collection.ObjectID:

check(someObjectId, Meteor.Collection.ObjectID)