b2811e50c5
The value here is unimportant on initialization since it's not looked at until the second navigation. However, sometimes in testing the `Location` service is mocked out, or the Router constructor manually called. Assuming `Location` exists in the constructor leads to test failures in `google3` therefore we initialize to a value that will not cause errors. PR Close #28376
Angular Router
Managing state transitions is one of the hardest parts of building applications. This is especially true on the web, where you also need to ensure that the state is reflected in the URL. In addition, we often want to split applications into multiple bundles and load them on demand. Doing this transparently isn’t trivial.
The Angular router is designed to solve these problems. Using the router, you can declaratively specify application state, manage state transitions while taking care of the URL, and load components on demand.
Guide
Read the dev guide here.