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Andrew Scott
7b367d9d90
Using `setTimeout` in the Router navigation pipeline creates fragile and unpredictable behavior. Additionally, it creates a new macrotask, which would trigger an unnecessary change detection in the application. This `setTimeout` was added in https://github.com/angular/angular/commit/15e397816f98ec16839c30fd5c1ea01c7444fb84. Both tests added in that commit still pass. Additionally, the comment for _why_ the `setTimeout` was added doesn't really explain how the described bug would occur. There has been a lot of work in the Router since then to stabalize edge case scenarios so it's possible it existed before but doesn't anymore. Removing this `setTimeout` revealed tests that relied on the navigation not completing. For example, the test suite did not have a route which matched the redirect, but the test passed because it ended before the redirect was flushed, so the `Router` never threw an error. Similar situations exist for the other use of `setTimeout` in the Route (the one in the location change listener). There were no other failures in TGP other than incorrectly written tests. BREAKING CHANGE: When a guard returns a `UrlTree`, the router would previously schedule the redirect navigation within a `setTimeout`. This timeout is now removed, which can result in test failures due to incorrectly written tests. Tests which perform navigations should ensure that all timeouts are flushed before making assertions. Tests should ensure they are capable of handling all redirects from the original navigation. PR Close #45735
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.