backbone-jasmine

sketch

Model = Backbone.Model.extend({
  url: '/something'
});

aModel = new Model({ id: 'else' });

FixturesSync = function(method, model, options) {
  var url = model.url || model.collection.url;
  switch (method) {
    case "read":
      return fixtures['read'][model.url][model.id];
      break;
    case "create":
      return fixtures[model.url]['create']; break;
//etc for "update" and "delete" cases
  }
  options.success(resp);
};

var fixtures = {
  'read' : {
    '/something' : {
      'else' : { // collection of properties }
    }
};

describe("how to test this", function() {
  beforeEach( function() {
    Backbone.sync = FixturesSync; // swap out the sync to map to fixtures
  });

  it('should work!', function() {} );
});