Prerender: Confirm ServiceWorkers are invoked for NoState Prefetch

chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc

Index: chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
diff --git a/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc b/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
index 6c1d72ff9bc201bdcb292665c6110df47712c3d7..a00ec8ff25077e03eb676a81d7cdc2361a72c8ba 100644
--- a/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
+++ b/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
@@ -20,6 +20,8 @@
 #include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
 #include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/service_worker_context.h"
+#include "content/public/browser/storage_partition.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/test/browser_test_utils.h"
 #include "net/base/escape.h"
@@ -33,6 +35,15 @@ using prerender::test_utils::DestructionWaiter;
 using prerender::test_utils::RequestCounter;
 using prerender::test_utils::TestPrerender;
 
+namespace {
+
+void ClosureOnUiThread(const base::Closure& callback) {
+  content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
+                                   callback);
+}
+
+}  // namespace
+
 namespace prerender {
 
 // These URLs used for test resources must be relative with the exception of
@@ -49,6 +60,8 @@ const char kPrefetchResponseHeaderCSP[] =
     "prerender/prefetch_response_csp.html";
 const char kPrefetchScript[] = "prerender/prefetch.js";
 const char kPrefetchScript2[] = "prerender/prefetch2.js";
+const char kServiceWorkerLoader[] = "prerender/service_worker.html";
+const char kServiceWorkerJavascript[] = "prerender/service_worker.js";
 const char kPrefetchSubresourceRedirectPage[] =
     "prerender/prefetch_subresource_redirect.html";
 
@@ -514,4 +527,36 @@ IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, IssuesIdlePriorityRequests) {
   script_counter.WaitForCount(1);
 }
 
+// Checks that a registered ServiceWorker (SW) without a renderer intercepts a
+// prefetch request.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, ServiceWorkerIntercept) {
+  // Register and launch a SW.
+  RequestCounter sw_counter;
+  CountRequestFor(kServiceWorkerJavascript, &sw_counter);
+  ui_test_utils::NavigateToURL(
+      current_browser(),
+      src_server()->GetURL(MakeAbsolute(kServiceWorkerLoader)));
+  sw_counter.WaitForCount(1);

[horo, 2017/01/05 05:33:58]

You have to wait the service worker to be activated.
Otherwise this test will be flaky on slow machines.

Use TitleWatcher and navigator.serviceWorker.ready.

-- prerender_nostate_prefetch_browsertest.cc --

  base::string16 expected_title = base::ASCIIToUTF16("READY");
  content::TitleWatcher title_watcher(GetActiveWebContents(), expected_title);
  ui_test_utils::NavigateToURL(
      current_browser(),
      src_server()->GetURL(MakeAbsolute(kServiceWorkerLoader)));
  EXPECT_EQ(expected_title, title_watcher.WaitAndGetTitle());


-- service_worker.html --

  <script type="text/javascript">
    window.addEventListener('load', function() {
      navigator.serviceWorker.register('/prerender/service_worker.js')
        .then(function(registration) {
          console.log('ServiceWorker registered');
          return navigator.serviceWorker.ready;
        })
        .then(function(registration) {
          document.title = 'READY';
        })
        .catch(function(err) {
          console.log(err);
        });
    });
  </script>

[mattcary, 2017/01/05 14:30:43]

Thanks! That seems much more reliable than just waiting for the js to be read.

+
+  // Stop the SW renderer process.
+  base::RunLoop run_loop;
+  content::StoragePartition* storage_partation =
+      content::BrowserContext::GetStoragePartitionForSite(
+          GetActiveWebContents()->GetBrowserContext(),
+          src_server()->GetURL(MakeAbsolute(kPrefetchPng)));
+  storage_partation->GetServiceWorkerContext()
+      ->StopAllServiceWorkersForOriginWithCallback(
+          src_server()->GetURL("/"),
+          base::Bind(&ClosureOnUiThread, run_loop.QuitClosure()));
+  run_loop.Run();
+
+  // The SW intercepts kPrefetchPage and replaces it with a body that contains
+  // an <img> tage for kPrefetchPng. This verifies that the SW ran correctly by
+  // observing the fetch of the image.
+  RequestCounter image_counter;
+  CountRequestFor(kPrefetchPng, &image_counter);
+  PrefetchFromFile(kPrefetchPage, FINAL_STATUS_NOSTATE_PREFETCH_FINISHED);
+  image_counter.WaitForCount(1);
+}
+
 }  // namespace prerender