Fix sw test (#386)

Author: kblok

lib/PuppeteerSharp.TestServer/wwwroot/serviceworkers/fetch/sw.html

@@ -1,4 +1,5 @@
 <link rel="stylesheet" href="./style.css">
 <script>
   navigator.serviceWorker.register('sw.js');
+  window.activationPromise = new Promise(resolve => navigator.serviceWorker.oncontrollerchange = resolve);
 </script>

lib/PuppeteerSharp.TestServer/wwwroot/serviceworkers/fetch/sw.js

@@ -1,3 +1,7 @@
 self.addEventListener('fetch', event => {
   event.respondWith(fetch(event.request));
+});
+
+self.addEventListener('activate', event => {
+  event.waitUntil(clients.claim());
 });

lib/PuppeteerSharp.Tests/NetworkTests/NetworkEventTests.cs

@@ -80,6 +80,7 @@ public async Task ResponseFromServiceWorker()
             Page.Response += (sender, e) => responses[e.Response.Url.Split('/').Last()] = e.Response;
             await Page.GoToAsync(TestConstants.ServerUrl + "/serviceworkers/fetch/sw.html",
                 waitUntil: new[] { WaitUntilNavigation.Networkidle2 });
+            await Page.EvaluateFunctionAsync("async () => await window.activationPromise");
             await Page.ReloadAsync();
 
             Assert.Equal(2, responses.Count);