When I am creating a simple website with node.js I am fine with using the view engine (eg. jade) and controllers that provide data to it (eg. simple todo list). However, if I d
Absolutely. Angular can still do a lot on your site even if you never utilize the $http service to talk to your server. You can still take advantage of the utilities for helping out with managing your DOM.
That said, most modern apps need to get data from the server. There are tons of reasons why you might need to do this. For example, if you had users that needed to sign up then you'd need to store their username and password somewhere. That somewhere would be in a database that only your server can access. Then your server would provide some URLs that you can talk to via Angular's $http service.
If you do have an app that makes calls to the server but you want to turn off the network communication for testing, you can mock the $http call responses. Angular provides an $httpBackend for that exact purpose. You can use it to set up dummy URLs that pretend to respond to your $http calls so that your $http calls don't know they aren't actually talking to a server.
authRequestHandler = $httpBackend.when('GET', '/auth.py')
.respond({userId: 'userX'}, {'A-Token': 'xxx'});
Perfect for testing your code without a REST backend during testing.