Example of stubbing a complex object

tests.js

describe('something', function() {
  var oldXrm;
  beforeEach(function() {
    oldXrm = Xrm;
    
    Xrm = {
      Page: {
        getAttribute: sinon.stub()
      }
    };
  });
  
  afterEach(function() {
    Xrm = oldXrm;
  });
  
  it('tests something', function() {
    var fakeAttribute = {
      getValue: function() { return 'something'; }
    };
    Xrm.Page.getAttribute.withArgs('name').returns(fakeAttribute);
    
    //test code here
  });
});