Waiting for network calls

In Chapter 3, Navigating through a website, we talked about requests and responses. Every page navigation begins with a request to a page. The server then processes that request and sends a response. That response generally is an HTML page, which has resources declared that need to be requested. The server will process each of those requests again and send many responses.

But that's not all. Modern apps will send requests to the server based on user actions. Take Google Maps: the user moves the mouse, and the page will need to request a new picture of the map without reloading the entire page.

We don't work on the Google Maps teams, but many users have reported that the home page sometimes doesn't load the product image after login. So, we could write a test to check that it should load an image. Oh… you thought we were going to test Google Maps? Not this time, sorry.

In this case, we can use waitForResponse(urlOrPredicate, ...