Bug 1845317 - Test case of offline fetch error propagation for workers. r=dom-worker-reviewers,smaug

Depends on D186125

Differential Revision: https://phabricator.services.mozilla.com/D184485

dom/workers/test/xpcshell/test_ext_worker_offline_fetch.js

@@ -0,0 +1,112 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+"use strict";
+
+const { TestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/TestUtils.sys.mjs"
+);
+
+const { AddonTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/AddonTestUtils.sys.mjs"
+);
+
+const { ExtensionTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/ExtensionXPCShellUtils.sys.mjs"
+);
+
+const { createHttpServer } = AddonTestUtils;
+
+// Force ServiceWorkerRegistrar to init by calling do_get_profile.
+// (This has to be called before AddonTestUtils.init, because it does
+// also call do_get_profile internally but it doesn't notify
+// profile-after-change).
+do_get_profile(true);
+
+AddonTestUtils.init(this);
+ExtensionTestUtils.init(this);
+
+const server = createHttpServer({ hosts: ["example.com"] });
+server.registerPathHandler("/dummy", (request, response) => {
+  response.setStatusLine(request.httpVersion, 200, "OK");
+  response.setHeader("Content-Type", "text/html", false);
+  response.write("dummy page");
+});
+
+add_setup(() => {
+  info("Making sure Services.io.offline is true");
+  // Explicitly setting Services.io.offline to true makes this test able
+  // to hit on Desktop builds the same issue that test_ext_cache_api.js
+  // was hitting on Android builds (Bug 1844825).
+  Services.io.offline = true;
+});
+
+// Regression test derived from Bug 1844825.
+add_task(async function test_fetch_request_from_ext_shared_worker() {
+  if (!WebExtensionPolicy.useRemoteWebExtensions) {
+    // Ensure RemoteWorkerService has been initialized in the main
+    // process.
+    Services.obs.notifyObservers(null, "profile-after-change");
+  }
+
+  const background = async function () {
+    const testUrl = `http://example.com/dummy`;
+    const worker = new SharedWorker("worker.js");
+    const { data: result } = await new Promise(resolve => {
+      worker.port.onmessage = resolve;
+      worker.port.postMessage(["worker-fetch-test", testUrl]);
+    });
+
+    browser.test.sendMessage("test-sharedworker-fetch:done", result);
+  };
+
+  const extension = ExtensionTestUtils.loadExtension({
+    background,
+    manifest: { permissions: ["http://example.com/*"] },
+    files: {
+      "worker.js": function () {
+        self.onconnect = evt => {
+          const port = evt.ports[0];
+          port.onmessage = async evt => {
+            let result = {};
+            let message;
+            try {
+              const [msg, url] = evt.data;
+              message = msg;
+              const response = await fetch(url);
+              dump(`fetch call resolved: ${response}\n`);
+              result.fetchResolvesTo = `${response}`;
+            } catch (err) {
+              dump(`fetch call rejected: ${err}\n`);
+              result.error = err.name;
+              throw err;
+            } finally {
+              port.postMessage([`${message}:result`, result]);
+            }
+          };
+        };
+      },
+    },
+  });
+
+  await extension.startup();
+  const result = await extension.awaitMessage("test-sharedworker-fetch:done");
+  if (Services.io.offline && WebExtensionPolicy.useRemoteWebExtensions) {
+    // If the network is offline and the extensions are running in the
+    // child extension process, expect the fetch call to be rejected
+    // with an TypeError.
+    Assert.deepEqual(
+      ["worker-fetch-test:result", { error: "TypeError" }],
+      result,
+      "fetch should have been rejected with an TypeError"
+    );
+  } else {
+    // If the network is not offline or the extension are running in the
+    // parent process, we expect the fetch call to resolve to a Response.
+    Assert.deepEqual(
+      ["worker-fetch-test:result", { fetchResolvesTo: "[object Response]" }],
+      result,
+      "fetch should have been resolved to a Response instance"
+    );
+  }
+  await extension.unload();
+});

dom/workers/test/xpcshell/xpcshell.ini

@@ -12,6 +12,8 @@ support-files =
 # it because there wouldn't be a global.tabTracker implementation as we would
 # expect in a real Firefox, Fenix or Thunderbird instance).
 firefox-appdir = browser
+[test_ext_worker_offline_fetch.js]
+firefox-appdir = browser
 [test_workers.js]
 [test_workers_clone_error.js]
 [test_fileReader.js]