How to make angular.js $http.post send an object with fields that are undefined

I am trying to use angular $http.post method to send an updated object to a node.js backend that uses mongoose.

I have a use-case that a user can make a field undefined, which is ok and should eventually make the mongoose to unset that field from the mongo document.

The problem is that angular.js $http.post actually just does not send any fields that their value is undefined.

This is my line for example:

return $http.post(`/api/update`, {
                field1: 1,
                field2: 'hey',
                field3: undefined
            });

If i then take a look using the developer tools, i will see that the sent object only contains the 2 first fields.

What should i do to make $http send also fields that are undefined?

via lobengula3rd