Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

15 files changed, 1333 insertions, 0 deletions

diff --git a/devtools/shared/network-observer/test/browser/browser.toml b/devtools/shared/network-observer/test/browser/browser.toml
new file mode 100644
index 0000000000..3b3b44aaae
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/browser.toml
@@ -0,0 +1,33 @@
+[DEFAULT]
+tags = "devtools"
+subsuite = "devtools"
+support-files = [
+  "head.js",
+  "doc_network-observer-missing-service-worker.html",
+  "doc_network-observer.html",
+  "gzipped.sjs",
+  "override.html",
+  "override.js",
+  "serviceworker.js",
+  "sjs_network-auth-listener-test-server.sjs",
+  "sjs_network-observer-test-server.sjs",
+]
+
+["browser_networkobserver.js"]
+skip-if = [
+  "http3", # Bug 1829298
+  "http2",
+]
+
+["browser_networkobserver_auth_listener.js"]
+skip-if = [
+  "debug", # Disabled for frequent leaks in Bug 1873571.
+  "asan",
+]
+
+["browser_networkobserver_invalid_constructor.js"]
+
+["browser_networkobserver_override.js"]
+
+["browser_networkobserver_serviceworker.js"]
+fail-if = ["true"] # Disabled until Bug 1267119 and Bug 1246289
diff --git a/devtools/shared/network-observer/test/browser/browser_networkobserver.js b/devtools/shared/network-observer/test/browser/browser_networkobserver.js
new file mode 100644
index 0000000000..8f81ef6f86
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/browser_networkobserver.js
@@ -0,0 +1,72 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const TEST_URL = URL_ROOT + "doc_network-observer.html";
+const REQUEST_URL =
+  URL_ROOT + `sjs_network-observer-test-server.sjs?sts=200&fmt=html`;
+
+// Check that the NetworkObserver can detect basic requests and calls the
+// onNetworkEvent callback when expected.
+add_task(async function testSingleRequest() {
+  await addTab(TEST_URL);
+
+  const onNetworkEvents = waitForNetworkEvents(REQUEST_URL, 1);
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [REQUEST_URL], _url => {
+    content.wrappedJSObject.fetch(_url);
+  });
+
+  const events = await onNetworkEvents;
+  is(events.length, 1, "Received the expected number of network events");
+});
+
+add_task(async function testMultipleRequests() {
+  await addTab(TEST_URL);
+  const EXPECTED_REQUESTS_COUNT = 5;
+
+  const onNetworkEvents = waitForNetworkEvents(
+    REQUEST_URL,
+    EXPECTED_REQUESTS_COUNT
+  );
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [REQUEST_URL, EXPECTED_REQUESTS_COUNT],
+    (_url, _count) => {
+      for (let i = 0; i < _count; i++) {
+        content.wrappedJSObject.fetch(_url);
+      }
+    }
+  );
+
+  const events = await onNetworkEvents;
+  is(
+    events.length,
+    EXPECTED_REQUESTS_COUNT,
+    "Received the expected number of network events"
+  );
+});
+
+add_task(async function testOnNetworkEventArguments() {
+  await addTab(TEST_URL);
+
+  const onNetworkEvent = new Promise(resolve => {
+    const networkObserver = new NetworkObserver({
+      ignoreChannelFunction: () => false,
+      onNetworkEvent: (...args) => {
+        resolve(args);
+        return createNetworkEventOwner();
+      },
+    });
+    registerCleanupFunction(() => networkObserver.destroy());
+  });
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [REQUEST_URL], _url => {
+    content.wrappedJSObject.fetch(_url);
+  });
+
+  const args = await onNetworkEvent;
+  is(args.length, 2, "Received two arguments");
+  is(typeof args[0], "object", "First argument is an object");
+  ok(args[1] instanceof Ci.nsIChannel, "Second argument is a channel");
+});
diff --git a/devtools/shared/network-observer/test/browser/browser_networkobserver_auth_listener.js b/devtools/shared/network-observer/test/browser/browser_networkobserver_auth_listener.js
new file mode 100644
index 0000000000..e3492c10ad
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/browser_networkobserver_auth_listener.js
@@ -0,0 +1,386 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { PromptTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/PromptTestUtils.sys.mjs"
+);
+
+const TEST_URL = URL_ROOT + "doc_network-observer.html";
+const AUTH_URL = URL_ROOT + `sjs_network-auth-listener-test-server.sjs`;
+
+// Correct credentials for sjs_network-auth-listener-test-server.sjs.
+const USERNAME = "guest";
+const PASSWORD = "guest";
+const BAD_PASSWORD = "bad";
+
+// NetworkEventOwner which will cancel all auth prompt requests.
+class AuthCancellingOwner extends NetworkEventOwner {
+  hasAuthPrompt = false;
+
+  onAuthPrompt(authDetails, authCallbacks) {
+    this.hasAuthPrompt = true;
+    authCallbacks.cancelAuthPrompt();
+  }
+}
+
+// NetworkEventOwner which will forward all auth prompt requests to the browser.
+class AuthForwardingOwner extends NetworkEventOwner {
+  hasAuthPrompt = false;
+
+  onAuthPrompt(authDetails, authCallbacks) {
+    this.hasAuthPrompt = true;
+    authCallbacks.forwardAuthPrompt();
+  }
+}
+
+// NetworkEventOwner which will answer provided credentials to auth prompts.
+class AuthCredentialsProvidingOwner extends NetworkEventOwner {
+  hasAuthPrompt = false;
+
+  constructor(channel, username, password) {
+    super();
+
+    this.channel = channel;
+    this.username = username;
+    this.password = password;
+  }
+
+  async onAuthPrompt(authDetails, authCallbacks) {
+    this.hasAuthPrompt = true;
+
+    // Providing credentials immediately can lead to intermittent failures.
+    // TODO: Investigate and remove.
+    // eslint-disable-next-line mozilla/no-arbitrary-setTimeout
+    await new Promise(r => setTimeout(r, 100));
+
+    await authCallbacks.provideAuthCredentials(this.username, this.password);
+  }
+
+  addResponseContent(content) {
+    super.addResponseContent();
+    this.responseContent = content.text;
+  }
+}
+
+add_task(async function testAuthRequestWithoutListener() {
+  cleanupAuthManager();
+  const tab = await addTab(TEST_URL);
+
+  const events = [];
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== AUTH_URL,
+    onNetworkEvent: event => {
+      const owner = new AuthForwardingOwner();
+      events.push(owner);
+      return owner;
+    },
+  });
+  registerCleanupFunction(() => networkObserver.destroy());
+
+  const onAuthPrompt = waitForAuthPrompt(tab);
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [AUTH_URL], _url => {
+    content.wrappedJSObject.fetch(_url);
+  });
+
+  info("Wait for a network event to be created");
+  await BrowserTestUtils.waitForCondition(() => events.length >= 1);
+  is(events.length, 1, "Received the expected number of network events");
+
+  info("Wait for the auth prompt to be displayed");
+  await onAuthPrompt;
+  Assert.equal(
+    getTabAuthPrompts(tab).length,
+    1,
+    "The auth prompt was not blocked by the network observer"
+  );
+
+  // The event owner should have been called for ResponseStart and EventTimings
+  assertEventOwner(events[0], {
+    hasResponseStart: true,
+    hasEventTimings: true,
+    hasServerTimings: true,
+  });
+
+  networkObserver.destroy();
+  gBrowser.removeTab(tab);
+});
+
+add_task(async function testAuthRequestWithForwardingListener() {
+  cleanupAuthManager();
+  const tab = await addTab(TEST_URL);
+
+  const events = [];
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== AUTH_URL,
+    onNetworkEvent: event => {
+      info("waitForNetworkEvents received a new event");
+      const owner = new AuthForwardingOwner();
+      events.push(owner);
+      return owner;
+    },
+  });
+  registerCleanupFunction(() => networkObserver.destroy());
+
+  info("Enable the auth prompt listener for this network observer");
+  networkObserver.setAuthPromptListenerEnabled(true);
+
+  const onAuthPrompt = waitForAuthPrompt(tab);
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [AUTH_URL], _url => {
+    content.wrappedJSObject.fetch(_url);
+  });
+
+  info("Wait for a network event to be received");
+  await BrowserTestUtils.waitForCondition(() => events.length >= 1);
+  is(events.length, 1, "Received the expected number of network events");
+
+  // The auth prompt should still be displayed since the network event owner
+  // forwards the auth notification immediately.
+  info("Wait for the auth prompt to be displayed");
+  await onAuthPrompt;
+  Assert.equal(
+    getTabAuthPrompts(tab).length,
+    1,
+    "The auth prompt was not blocked by the network observer"
+  );
+
+  // The event owner should have been called for ResponseStart, EventTimings and
+  // AuthPrompt
+  assertEventOwner(events[0], {
+    hasResponseStart: true,
+    hasEventTimings: true,
+    hasAuthPrompt: true,
+    hasServerTimings: true,
+  });
+
+  networkObserver.destroy();
+  gBrowser.removeTab(tab);
+});
+
+add_task(async function testAuthRequestWithCancellingListener() {
+  cleanupAuthManager();
+  const tab = await addTab(TEST_URL);
+
+  const events = [];
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== AUTH_URL,
+    onNetworkEvent: event => {
+      const owner = new AuthCancellingOwner();
+      events.push(owner);
+      return owner;
+    },
+  });
+  registerCleanupFunction(() => networkObserver.destroy());
+
+  info("Enable the auth prompt listener for this network observer");
+  networkObserver.setAuthPromptListenerEnabled(true);
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [AUTH_URL], _url => {
+    content.wrappedJSObject.fetch(_url);
+  });
+
+  info("Wait for a network event to be received");
+  await BrowserTestUtils.waitForCondition(() => events.length >= 1);
+  is(events.length, 1, "Received the expected number of network events");
+
+  await BrowserTestUtils.waitForCondition(
+    () => events[0].hasResponseContent && events[0].hasSecurityInfo
+  );
+
+  // The auth prompt should not be displayed since the authentication was
+  // cancelled.
+  ok(
+    !getTabAuthPrompts(tab).length,
+    "The auth prompt was cancelled by the network event owner"
+  );
+
+  assertEventOwner(events[0], {
+    hasResponseStart: true,
+    hasResponseContent: true,
+    hasEventTimings: true,
+    hasServerTimings: true,
+    hasAuthPrompt: true,
+    hasSecurityInfo: true,
+  });
+
+  networkObserver.destroy();
+  gBrowser.removeTab(tab);
+});
+
+add_task(async function testAuthRequestWithWrongCredentialsListener() {
+  cleanupAuthManager();
+  const tab = await addTab(TEST_URL);
+
+  const events = [];
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== AUTH_URL,
+    onNetworkEvent: (event, channel) => {
+      const owner = new AuthCredentialsProvidingOwner(
+        channel,
+        USERNAME,
+        BAD_PASSWORD
+      );
+      events.push(owner);
+      return owner;
+    },
+  });
+  registerCleanupFunction(() => networkObserver.destroy());
+
+  info("Enable the auth prompt listener for this network observer");
+  networkObserver.setAuthPromptListenerEnabled(true);
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [AUTH_URL], _url => {
+    content.wrappedJSObject.fetch(_url);
+  });
+
+  info("Wait for all network events to be received");
+  await BrowserTestUtils.waitForCondition(() => events.length >= 1);
+  is(events.length, 1, "Received the expected number of network events");
+
+  // Wait for authPrompt to be handled
+  await BrowserTestUtils.waitForCondition(() => events[0].hasAuthPrompt);
+
+  // The auth prompt should not be displayed since the authentication was
+  // fulfilled.
+  ok(
+    !getTabAuthPrompts(tab).length,
+    "The auth prompt was handled by the network event owner"
+  );
+
+  assertEventOwner(events[0], {
+    hasAuthPrompt: true,
+    hasResponseStart: true,
+    hasEventTimings: true,
+    hasServerTimings: true,
+  });
+
+  networkObserver.destroy();
+  gBrowser.removeTab(tab);
+});
+
+add_task(async function testAuthRequestWithCredentialsListener() {
+  cleanupAuthManager();
+  const tab = await addTab(TEST_URL);
+
+  const events = [];
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== AUTH_URL,
+    onNetworkEvent: (event, channel) => {
+      const owner = new AuthCredentialsProvidingOwner(
+        channel,
+        USERNAME,
+        PASSWORD
+      );
+      events.push(owner);
+      return owner;
+    },
+  });
+  registerCleanupFunction(() => networkObserver.destroy());
+
+  info("Enable the auth prompt listener for this network observer");
+  networkObserver.setAuthPromptListenerEnabled(true);
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [AUTH_URL], _url => {
+    content.wrappedJSObject.fetch(_url);
+  });
+
+  // TODO: At the moment, providing credentials will result in additional
+  // network events collected by the NetworkObserver, whereas we would expect
+  // to keep the same event.
+  // For successful auth prompts, we receive an additional event.
+  // The last event will contain the responseContent flag.
+  info("Wait for all network events to be received");
+  await BrowserTestUtils.waitForCondition(() => events.length >= 2);
+  is(events.length, 2, "Received the expected number of network events");
+
+  // Since the auth prompt was canceled we should also receive the security
+  // information and the response content.
+  await BrowserTestUtils.waitForCondition(
+    () => events[1].hasResponseContent && events[1].hasSecurityInfo
+  );
+
+  // The auth prompt should not be displayed since the authentication was
+  // fulfilled.
+  ok(
+    !getTabAuthPrompts(tab).length,
+    "The auth prompt was handled by the network event owner"
+  );
+
+  assertEventOwner(events[1], {
+    hasResponseStart: true,
+    hasEventTimings: true,
+    hasSecurityInfo: true,
+    hasServerTimings: true,
+    hasResponseContent: true,
+  });
+
+  is(events[1].responseContent, "success", "Auth prompt was successful");
+
+  networkObserver.destroy();
+  gBrowser.removeTab(tab);
+});
+
+function assertEventOwner(event, expectedFlags) {
+  is(
+    event.hasResponseStart,
+    !!expectedFlags.hasResponseStart,
+    "network event has the expected ResponseStart flag"
+  );
+  is(
+    event.hasEventTimings,
+    !!expectedFlags.hasEventTimings,
+    "network event has the expected EventTimings flag"
+  );
+  is(
+    event.hasAuthPrompt,
+    !!expectedFlags.hasAuthPrompt,
+    "network event has the expected AuthPrompt flag"
+  );
+  is(
+    event.hasResponseCache,
+    !!expectedFlags.hasResponseCache,
+    "network event has the expected ResponseCache flag"
+  );
+  is(
+    event.hasResponseContent,
+    !!expectedFlags.hasResponseContent,
+    "network event has the expected ResponseContent flag"
+  );
+  is(
+    event.hasSecurityInfo,
+    !!expectedFlags.hasSecurityInfo,
+    "network event has the expected SecurityInfo flag"
+  );
+  is(
+    event.hasServerTimings,
+    !!expectedFlags.hasServerTimings,
+    "network event has the expected ServerTimings flag"
+  );
+}
+
+function getTabAuthPrompts(tab) {
+  const tabDialogBox = gBrowser.getTabDialogBox(tab.linkedBrowser);
+  return tabDialogBox
+    .getTabDialogManager()
+    ._dialogs.filter(
+      d => d.frameContentWindow?.Dialog.args.promptType == "promptUserAndPass"
+    );
+}
+
+function waitForAuthPrompt(tab) {
+  return PromptTestUtils.waitForPrompt(tab.linkedBrowser, {
+    modalType: Services.prompt.MODAL_TYPE_TAB,
+    promptType: "promptUserAndPass",
+  });
+}
+
+// Cleanup potentially stored credentials before running any test.
+function cleanupAuthManager() {
+  const authManager = SpecialPowers.Cc[
+    "@mozilla.org/network/http-auth-manager;1"
+  ].getService(SpecialPowers.Ci.nsIHttpAuthManager);
+  authManager.clearAll();
+}
diff --git a/devtools/shared/network-observer/test/browser/browser_networkobserver_invalid_constructor.js b/devtools/shared/network-observer/test/browser/browser_networkobserver_invalid_constructor.js
new file mode 100644
index 0000000000..76a93d938a
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/browser_networkobserver_invalid_constructor.js
@@ -0,0 +1,49 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Check that the NetworkObserver constructor validates its arguments.
+add_task(async function testInvalidConstructorArguments() {
+  Assert.throws(
+    () => new NetworkObserver(),
+    /Expected "ignoreChannelFunction" to be a function, got undefined/,
+    "NetworkObserver constructor should throw if no argument was provided"
+  );
+
+  Assert.throws(
+    () => new NetworkObserver({}),
+    /Expected "ignoreChannelFunction" to be a function, got undefined/,
+    "NetworkObserver constructor should throw if ignoreChannelFunction was not provided"
+  );
+
+  const invalidValues = [null, true, false, 12, "str", ["arr"], { obj: "obj" }];
+  for (const invalidValue of invalidValues) {
+    Assert.throws(
+      () => new NetworkObserver({ ignoreChannelFunction: invalidValue }),
+      /Expected "ignoreChannelFunction" to be a function, got/,
+      `NetworkObserver constructor should throw if a(n) ${typeof invalidValue} was provided for ignoreChannelFunction`
+    );
+  }
+
+  const EMPTY_FN = () => {};
+  Assert.throws(
+    () => new NetworkObserver({ ignoreChannelFunction: EMPTY_FN }),
+    /Expected "onNetworkEvent" to be a function, got undefined/,
+    "NetworkObserver constructor should throw if onNetworkEvent was not provided"
+  );
+
+  // Now we will pass a function for `ignoreChannelFunction`, and will do the
+  // same tests for onNetworkEvent
+  for (const invalidValue of invalidValues) {
+    Assert.throws(
+      () =>
+        new NetworkObserver({
+          ignoreChannelFunction: EMPTY_FN,
+          onNetworkEvent: invalidValue,
+        }),
+      /Expected "onNetworkEvent" to be a function, got/,
+      `NetworkObserver constructor should throw if a(n) ${typeof invalidValue} was provided for onNetworkEvent`
+    );
+  }
+});
diff --git a/devtools/shared/network-observer/test/browser/browser_networkobserver_override.js b/devtools/shared/network-observer/test/browser/browser_networkobserver_override.js
new file mode 100644
index 0000000000..3b00c4b2e9
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/browser_networkobserver_override.js
@@ -0,0 +1,179 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const TEST_URL = URL_ROOT + "doc_network-observer.html";
+const REQUEST_URL =
+  URL_ROOT + `sjs_network-observer-test-server.sjs?sts=200&fmt=html`;
+const GZIPPED_REQUEST_URL = URL_ROOT + `gzipped.sjs`;
+const OVERRIDE_FILENAME = "override.js";
+const OVERRIDE_HTML_FILENAME = "override.html";
+
+add_task(async function testLocalOverride() {
+  await addTab(TEST_URL);
+
+  let eventsCount = 0;
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== REQUEST_URL,
+    onNetworkEvent: event => {
+      info("received a network event");
+      eventsCount++;
+      return createNetworkEventOwner(event);
+    },
+  });
+
+  const overrideFile = getChromeDir(getResolvedURI(gTestPath));
+  overrideFile.append(OVERRIDE_FILENAME);
+  info(" override " + REQUEST_URL + " to " + overrideFile.path + "\n");
+  networkObserver.override(REQUEST_URL, overrideFile.path);
+
+  info("Assert that request and cached request are overriden");
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [REQUEST_URL],
+    async _url => {
+      const request = await content.wrappedJSObject.fetch(_url);
+      const requestcontent = await request.text();
+      is(
+        requestcontent,
+        `"use strict";\ndocument.title = "evaluated";\n`,
+        "the request content has been overriden"
+      );
+      const secondRequest = await content.wrappedJSObject.fetch(_url);
+      const secondRequestcontent = await secondRequest.text();
+      is(
+        secondRequestcontent,
+        `"use strict";\ndocument.title = "evaluated";\n`,
+        "the cached request content has been overriden"
+      );
+    }
+  );
+
+  info("Assert that JS scripts can be overriden");
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [REQUEST_URL],
+    async _url => {
+      const script = await content.document.createElement("script");
+      const onLoad = new Promise(resolve =>
+        script.addEventListener("load", resolve, { once: true })
+      );
+      script.src = _url;
+      content.document.body.appendChild(script);
+      await onLoad;
+      is(
+        content.document.title,
+        "evaluated",
+        "The <script> tag content has been overriden and correctly evaluated"
+      );
+    }
+  );
+
+  await BrowserTestUtils.waitForCondition(() => eventsCount >= 1);
+
+  networkObserver.destroy();
+});
+
+add_task(async function testHtmlFileOverride() {
+  let eventsCount = 0;
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== TEST_URL,
+    onNetworkEvent: event => {
+      info("received a network event");
+      eventsCount++;
+      return createNetworkEventOwner(event);
+    },
+  });
+
+  const overrideFile = getChromeDir(getResolvedURI(gTestPath));
+  overrideFile.append(OVERRIDE_HTML_FILENAME);
+  info(" override " + TEST_URL + " to " + overrideFile.path + "\n");
+  networkObserver.override(TEST_URL, overrideFile.path);
+
+  await addTab(TEST_URL);
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [TEST_URL],
+    async pageUrl => {
+      is(
+        content.document.documentElement.outerHTML,
+        "<html><head></head><body>Overriden!\n</body></html>",
+        "The content of the HTML has been overriden"
+      );
+      // For now, all overriden request have their location changed to an internal data: URI
+      // Bug xxx aims at keeping the original URI.
+      todo_is(
+        content.location.href,
+        pageUrl,
+        "The location of the page is still the original one"
+      );
+    }
+  );
+  await BrowserTestUtils.waitForCondition(() => eventsCount >= 1);
+  networkObserver.destroy();
+});
+
+// Exact same test, but with a gzipped request, which requires very special treatment
+add_task(async function testLocalOverrideGzipped() {
+  await addTab(TEST_URL);
+
+  let eventsCount = 0;
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel => channel.URI.spec !== GZIPPED_REQUEST_URL,
+    onNetworkEvent: event => {
+      info("received a network event");
+      eventsCount++;
+      return createNetworkEventOwner(event);
+    },
+  });
+
+  const overrideFile = getChromeDir(getResolvedURI(gTestPath));
+  overrideFile.append(OVERRIDE_FILENAME);
+  info(" override " + GZIPPED_REQUEST_URL + " to " + overrideFile.path + "\n");
+  networkObserver.override(GZIPPED_REQUEST_URL, overrideFile.path);
+
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [GZIPPED_REQUEST_URL],
+    async _url => {
+      const request = await content.wrappedJSObject.fetch(_url);
+      const requestcontent = await request.text();
+      is(
+        requestcontent,
+        `"use strict";\ndocument.title = "evaluated";\n`,
+        "the request content has been overriden"
+      );
+      const secondRequest = await content.wrappedJSObject.fetch(_url);
+      const secondRequestcontent = await secondRequest.text();
+      is(
+        secondRequestcontent,
+        `"use strict";\ndocument.title = "evaluated";\n`,
+        "the cached request content has been overriden"
+      );
+    }
+  );
+
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [GZIPPED_REQUEST_URL],
+    async _url => {
+      const script = await content.document.createElement("script");
+      const onLoad = new Promise(resolve =>
+        script.addEventListener("load", resolve, { once: true })
+      );
+      script.src = _url;
+      content.document.body.appendChild(script);
+      await onLoad;
+      is(
+        content.document.title,
+        "evaluated",
+        "The <script> tag content has been overriden and correctly evaluated"
+      );
+    }
+  );
+
+  await BrowserTestUtils.waitForCondition(() => eventsCount >= 1);
+
+  networkObserver.destroy();
+});
diff --git a/devtools/shared/network-observer/test/browser/browser_networkobserver_serviceworker.js b/devtools/shared/network-observer/test/browser/browser_networkobserver_serviceworker.js
new file mode 100644
index 0000000000..1680dc6005
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/browser_networkobserver_serviceworker.js
@@ -0,0 +1,113 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Tests that all the expected service worker requests are received
+// by the network observer.
+add_task(async function testServiceWorkerSuccessRequests() {
+  await addTab(URL_ROOT + "doc_network-observer.html");
+
+  const REQUEST_URL =
+    URL_ROOT + `sjs_network-observer-test-server.sjs?sts=200&fmt=`;
+
+  const EXPECTED_REQUESTS = [
+    // The main service worker script request
+    `https://example.com/browser/devtools/shared/network-observer/test/browser/serviceworker.js`,
+    // The requests intercepted by the service worker
+    REQUEST_URL + "js",
+    REQUEST_URL + "css",
+    // The request initiated by the service worker
+    REQUEST_URL + "json",
+  ];
+
+  const onNetworkEvents = waitForNetworkEvents(null, 4);
+
+  info("Register the service worker and send requests...");
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [REQUEST_URL],
+    async url => {
+      await content.wrappedJSObject.registerServiceWorker();
+      content.wrappedJSObject.fetch(url + "js");
+      content.wrappedJSObject.fetch(url + "css");
+    }
+  );
+  const events = await onNetworkEvents;
+
+  is(events.length, 4, "Received the expected number of network events");
+  for (const { options, channel } of events) {
+    info(`Assert the info for the request from ${channel.URI.spec}`);
+    ok(
+      EXPECTED_REQUESTS.includes(channel.URI.spec),
+      `The request for ${channel.URI.spec} is an expected service worker request`
+    );
+    Assert.notStrictEqual(
+      channel.loadInfo.browsingContextID,
+      0,
+      `The request for ${channel.URI.spec} has a Browsing Context ID of ${channel.loadInfo.browsingContextID}`
+    );
+    // The main service worker script request is not from the service worker
+    if (channel.URI.spec.includes("serviceworker.js")) {
+      ok(
+        !options.fromServiceWorker,
+        `The request for ${channel.URI.spec} is not from the service worker\n`
+      );
+    } else {
+      ok(
+        options.fromServiceWorker,
+        `The request for ${channel.URI.spec} is from the service worker\n`
+      );
+    }
+  }
+
+  info("Unregistering the service worker...");
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], async function () {
+    await content.wrappedJSObject.unregisterServiceWorker();
+  });
+});
+
+// Tests that the expected failed service worker request is received by the network observer.
+add_task(async function testServiceWorkerFailedRequests() {
+  await addTab(URL_ROOT + "doc_network-observer-missing-service-worker.html");
+
+  const REQUEST_URL =
+    URL_ROOT + `sjs_network-observer-test-server.sjs?sts=200&fmt=js`;
+
+  const EXPECTED_REQUESTS = [
+    // The main service worker script request which should be missing
+    "https://example.com/browser/devtools/shared/network-observer/test/browser/serviceworker-missing.js",
+    // A notrmal request
+    "https://example.com/browser/devtools/shared/network-observer/test/browser/sjs_network-observer-test-server.sjs?sts=200&fmt=js",
+  ];
+
+  const onNetworkEvents = waitForNetworkEvents(null, 2);
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [REQUEST_URL],
+    async url => {
+      await content.wrappedJSObject.registerServiceWorker();
+      content.wrappedJSObject.fetch(url);
+    }
+  );
+
+  const events = await onNetworkEvents;
+  is(events.length, 2, "Received the expected number of network events");
+
+  for (const { options, channel } of events) {
+    info(`Assert the info for the request from ${channel.URI.spec}`);
+    ok(
+      EXPECTED_REQUESTS.includes(channel.URI.spec),
+      `The request for ${channel.URI.spec} is an expected request`
+    );
+    Assert.notStrictEqual(
+      channel.loadInfo.browsingContextID,
+      0,
+      `The request for ${channel.URI.spec} has a Browsing Context ID of ${channel.loadInfo.browsingContextID}`
+    );
+    ok(
+      !options.fromServiceWorker,
+      `The request for ${channel.URI.spec} is not from the service worker\n`
+    );
+  }
+});
diff --git a/devtools/shared/network-observer/test/browser/doc_network-observer-missing-service-worker.html b/devtools/shared/network-observer/test/browser/doc_network-observer-missing-service-worker.html
new file mode 100644
index 0000000000..396e51677c
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/doc_network-observer-missing-service-worker.html
@@ -0,0 +1,32 @@
+<!-- Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/ -->
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8" />
+    <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
+    <meta http-equiv="Pragma" content="no-cache" />
+    <meta http-equiv="Expires" content="0" />
+    <title>Network Observer missing service worker test page</title>
+  </head>
+
+  <body>
+    <p>Network Observer test page</p>
+    <script type="text/javascript">
+      /* exported registerServiceWorker */
+      "use strict";
+
+      function registerServiceWorker() {
+        const sw = navigator.serviceWorker;
+        // NOTE: This service worker file does not exist which enables testing
+        // that a 404 requests is received.
+        return sw.register("serviceworker-missing.js")
+          .then(registration => {
+            throw new Error("The Service Worker file should not exist");
+          }).catch(err => {
+            console.log("Registration failed as expected");
+          });
+      }
+    </script>
+  </body>
+</html>
diff --git a/devtools/shared/network-observer/test/browser/doc_network-observer.html b/devtools/shared/network-observer/test/browser/doc_network-observer.html
new file mode 100644
index 0000000000..2ca400e0ae
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/doc_network-observer.html
@@ -0,0 +1,49 @@
+<!-- Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/ -->
+<!doctype html>
+
+<html>
+  <head>
+    <meta charset="utf-8"/>
+    <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
+    <meta http-equiv="Pragma" content="no-cache" />
+    <meta http-equiv="Expires" content="0" />
+    <title>Network Observer test page</title>
+  </head>
+  <body>
+    <p>Network Observer test page</p>
+    <script type="text/javascript">
+      /* exported registerServiceWorker, unregisterServiceWorker */
+      "use strict";
+
+        let swRegistration;
+
+        function registerServiceWorker() {
+          const sw = navigator.serviceWorker;
+          return sw.register("serviceworker.js")
+            .then(registration => {
+              swRegistration = registration;
+              console.log("Registered, scope is:", registration.scope);
+              return sw.ready;
+            }).then(() => {
+              // wait until the page is controlled
+              return new Promise(resolve => {
+                if (sw.controller) {
+                  resolve();
+                } else {
+                  sw.addEventListener("controllerchange", function () {
+                    resolve();
+                  }, { once: true });
+                }
+              });
+            }).catch(err => {
+              console.error("Registration failed");
+            });
+        }
+
+        function unregisterServiceWorker() {
+          return swRegistration.unregister();
+        }
+    </script>
+  </body>
+</html>
diff --git a/devtools/shared/network-observer/test/browser/gzipped.sjs b/devtools/shared/network-observer/test/browser/gzipped.sjs
new file mode 100644
index 0000000000..09d0b249b1
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/gzipped.sjs
@@ -0,0 +1,44 @@
+"use strict";
+
+function gzipCompressString(string, obs) {
+  const scs = Cc["@mozilla.org/streamConverters;1"].getService(
+    Ci.nsIStreamConverterService
+  );
+  const listener = Cc["@mozilla.org/network/stream-loader;1"].createInstance(
+    Ci.nsIStreamLoader
+  );
+  listener.init(obs);
+  const converter = scs.asyncConvertData(
+    "uncompressed",
+    "gzip",
+    listener,
+    null
+  );
+  const stringStream = Cc[
+    "@mozilla.org/io/string-input-stream;1"
+  ].createInstance(Ci.nsIStringInputStream);
+  stringStream.data = string;
+  converter.onStartRequest(null, null);
+  converter.onDataAvailable(null, stringStream, 0, string.length);
+  converter.onStopRequest(null, null, null);
+}
+
+const ORIGINAL_JS_CONTENT = `console.log("original javascript content");`;
+
+function handleRequest(request, response) {
+  response.processAsync();
+
+  // Generate data
+  response.setHeader("Content-Type", "application/javascript", false);
+  response.setHeader("Content-Encoding", "gzip", false);
+
+  const observer = {
+    onStreamComplete(loader, context, status, length, result) {
+      const buffer = String.fromCharCode.apply(this, result);
+      response.setHeader("Content-Length", "" + buffer.length, false);
+      response.write(buffer);
+      response.finish();
+    },
+  };
+  gzipCompressString(ORIGINAL_JS_CONTENT, observer);
+}
diff --git a/devtools/shared/network-observer/test/browser/head.js b/devtools/shared/network-observer/test/browser/head.js
new file mode 100644
index 0000000000..deb7becff6
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/head.js
@@ -0,0 +1,123 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+ChromeUtils.defineESModuleGetters(this, {
+  NetworkObserver:
+    "resource://devtools/shared/network-observer/NetworkObserver.sys.mjs",
+});
+
+const TEST_DIR = gTestPath.substr(0, gTestPath.lastIndexOf("/"));
+const CHROME_URL_ROOT = TEST_DIR + "/";
+const URL_ROOT = CHROME_URL_ROOT.replace(
+  "chrome://mochitests/content/",
+  "https://example.com/"
+);
+
+/**
+ * Load the provided url in an existing browser.
+ * Returns a promise which will resolve when the page is loaded.
+ *
+ * @param {Browser} browser
+ *     The browser element where the URL should be loaded.
+ * @param {String} url
+ *     The URL to load in the new tab
+ */
+async function loadURL(browser, url) {
+  const loaded = BrowserTestUtils.browserLoaded(browser);
+  BrowserTestUtils.startLoadingURIString(browser, url);
+  return loaded;
+}
+
+/**
+ * Create a new foreground tab loading the provided url.
+ * Returns a promise which will resolve when the page is loaded.
+ *
+ * @param {String} url
+ *     The URL to load in the new tab
+ */
+async function addTab(url) {
+  const tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, url);
+  registerCleanupFunction(() => {
+    gBrowser.removeTab(tab);
+  });
+  return tab;
+}
+
+/**
+ * Base network event owner class implementing all mandatory callbacks and
+ * keeping track of which callbacks have been called.
+ */
+class NetworkEventOwner {
+  hasEventTimings = false;
+  hasResponseCache = false;
+  hasResponseContent = false;
+  hasResponseStart = false;
+  hasSecurityInfo = false;
+  hasServerTimings = false;
+
+  addEventTimings() {
+    this.hasEventTimings = true;
+  }
+  addResponseCache() {
+    this.hasResponseCache = true;
+  }
+  addResponseContent() {
+    this.hasResponseContent = true;
+  }
+  addResponseStart() {
+    this.hasResponseStart = true;
+  }
+  addSecurityInfo() {
+    this.hasSecurityInfo = true;
+  }
+  addServerTimings() {
+    this.hasServerTimings = true;
+  }
+  addServiceWorkerTimings() {
+    this.hasServiceWorkerTimings = true;
+  }
+}
+
+/**
+ * Create a simple network event owner, with mock implementations of all
+ * the expected APIs for a NetworkEventOwner.
+ */
+function createNetworkEventOwner(event) {
+  return new NetworkEventOwner();
+}
+
+/**
+ * Wait for network events matching the provided URL, until the count reaches
+ * the provided expected count.
+ *
+ * @param {string|null} expectedUrl
+ *     The URL which should be monitored by the NetworkObserver.If set to null watch for
+ *      all requests
+ * @param {number} expectedRequestsCount
+ *     How many different events (requests) are expected.
+ * @returns {Promise}
+ *     A promise which will resolve with an array of network event owners, when
+ *     the expected event count is reached.
+ */
+async function waitForNetworkEvents(expectedUrl = null, expectedRequestsCount) {
+  const events = [];
+  const networkObserver = new NetworkObserver({
+    ignoreChannelFunction: channel =>
+      expectedUrl ? channel.URI.spec !== expectedUrl : false,
+    onNetworkEvent: () => {
+      info("waitForNetworkEvents received a new event");
+      const owner = createNetworkEventOwner();
+      events.push(owner);
+      return owner;
+    },
+  });
+  registerCleanupFunction(() => networkObserver.destroy());
+
+  info("Wait until the events count reaches " + expectedRequestsCount);
+  await BrowserTestUtils.waitForCondition(
+    () => events.length >= expectedRequestsCount
+  );
+  return events;
+}
diff --git a/devtools/shared/network-observer/test/browser/override.html b/devtools/shared/network-observer/test/browser/override.html
new file mode 100644
index 0000000000..0e3878e313
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/override.html
@@ -0,0 +1 @@
+<html><head></head><body>Overriden!</body></html>
diff --git a/devtools/shared/network-observer/test/browser/override.js b/devtools/shared/network-observer/test/browser/override.js
new file mode 100644
index 0000000000..7b000fcd0f
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/override.js
@@ -0,0 +1,2 @@
+"use strict";
+document.title = "evaluated";
diff --git a/devtools/shared/network-observer/test/browser/serviceworker.js b/devtools/shared/network-observer/test/browser/serviceworker.js
new file mode 100644
index 0000000000..3389581fb0
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/serviceworker.js
@@ -0,0 +1,23 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+self.addEventListener("activate", async event => {
+  (
+    await fetch(
+      "https://example.com/browser/devtools/shared/network-observer/test/browser/sjs_network-observer-test-server.sjs?sts=200&fmt=json"
+    )
+  )
+    .json()
+    .then(() => console.log("json downloaded"));
+  // start controlling the already loaded page
+  event.waitUntil(self.clients.claim());
+});
+
+self.addEventListener("fetch", event => {
+  const response = new Response("Service worker response", {
+    statusText: "OK",
+  });
+  event.respondWith(response);
+});
diff --git a/devtools/shared/network-observer/test/browser/sjs_network-auth-listener-test-server.sjs b/devtools/shared/network-observer/test/browser/sjs_network-auth-listener-test-server.sjs
new file mode 100644
index 0000000000..028a26ebfe
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/sjs_network-auth-listener-test-server.sjs
@@ -0,0 +1,31 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+function handleRequest(request, response) {
+  let body;
+
+  // Expect guest/guest as correct credentials, but `btoa` is unavailable in sjs
+  //   "Z3Vlc3Q6Z3Vlc3Q=" == btoa("guest:guest")
+  const expectedHeader = "Basic Z3Vlc3Q6Z3Vlc3Q=";
+
+  // correct login credentials provided
+  if (
+    request.hasHeader("Authorization") &&
+    request.getHeader("Authorization") == expectedHeader
+  ) {
+    response.setStatusLine(request.httpVersion, 200, "OK, authorized");
+    response.setHeader("Content-Type", "text", false);
+
+    body = "success";
+  } else {
+    // incorrect credentials
+    response.setStatusLine(request.httpVersion, 401, "Unauthorized");
+    response.setHeader("WWW-Authenticate", 'Basic realm="secret"', false);
+    response.setHeader("Content-Type", "text", false);
+
+    body = "failed";
+  }
+  response.bodyOutputStream.write(body, body.length);
+}
diff --git a/devtools/shared/network-observer/test/browser/sjs_network-observer-test-server.sjs b/devtools/shared/network-observer/test/browser/sjs_network-observer-test-server.sjs
new file mode 100644
index 0000000000..b0947cadd1
--- /dev/null
+++ b/devtools/shared/network-observer/test/browser/sjs_network-observer-test-server.sjs
@@ -0,0 +1,196 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Simple server which can handle several response types and states.
+// Trimmed down from devtools/client/netmonitor/test/sjs_content-type-test-server.sjs
+// Additional features can be ported if needed.
+function handleRequest(request, response) {
+  response.processAsync();
+
+  const params = request.queryString.split("&");
+  const format = (params.filter(s => s.includes("fmt="))[0] || "").split(
+    "="
+  )[1];
+  const status =
+    (params.filter(s => s.includes("sts="))[0] || "").split("=")[1] || 200;
+
+  const cacheExpire = 60; // seconds
+
+  function setCacheHeaders() {
+    if (status != 304) {
+      response.setHeader(
+        "Cache-Control",
+        "no-cache, no-store, must-revalidate"
+      );
+      response.setHeader("Pragma", "no-cache");
+      response.setHeader("Expires", "0");
+      return;
+    }
+
+    response.setHeader("Expires", Date(Date.now() + cacheExpire * 1000), false);
+  }
+
+  let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+
+  timer.initWithCallback(
+    // eslint-disable-next-line complexity
+    () => {
+      // to avoid garbage collection
+      timer = null;
+      switch (format) {
+        case "txt": {
+          response.setStatusLine(request.httpVersion, status, "DA DA DA");
+          response.setHeader("Content-Type", "text/plain", false);
+          setCacheHeaders();
+
+          function convertToUtf8(str) {
+            return String.fromCharCode(...new TextEncoder().encode(str));
+          }
+
+          // This script must be evaluated as UTF-8 for this to write out the
+          // bytes of the string in UTF-8.  If it's evaluated as Latin-1, the
+          // written bytes will be the result of UTF-8-encoding this string
+          // *twice*.
+          const data = "Братан, ты вообще качаешься?";
+          const stringOfUtf8Bytes = convertToUtf8(data);
+          response.write(stringOfUtf8Bytes);
+
+          response.finish();
+          break;
+        }
+        case "xml": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "text/xml; charset=utf-8", false);
+          setCacheHeaders();
+          response.write("<label value='greeting'>Hello XML!</label>");
+          response.finish();
+          break;
+        }
+        case "html": {
+          const content = (
+            params.filter(s => s.includes("res="))[0] || ""
+          ).split("=")[1];
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "text/html; charset=utf-8", false);
+          setCacheHeaders();
+          response.write(content || "<p>Hello HTML!</p>");
+          response.finish();
+          break;
+        }
+        case "xhtml": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader(
+            "Content-Type",
+            "application/xhtml+xml; charset=utf-8",
+            false
+          );
+          setCacheHeaders();
+          response.write("<p>Hello XHTML!</p>");
+          response.finish();
+          break;
+        }
+        case "html-long": {
+          const str = new Array(102400 /* 100 KB in bytes */).join(".");
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "text/html; charset=utf-8", false);
+          setCacheHeaders();
+          response.write("<p>" + str + "</p>");
+          response.finish();
+          break;
+        }
+        case "css": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "text/css; charset=utf-8", false);
+          setCacheHeaders();
+          response.write("body:pre { content: 'Hello CSS!' }");
+          response.finish();
+          break;
+        }
+        case "js": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader(
+            "Content-Type",
+            "application/javascript; charset=utf-8",
+            false
+          );
+          setCacheHeaders();
+          response.write("function() { return 'Hello JS!'; }");
+          response.finish();
+          break;
+        }
+        case "json": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader(
+            "Content-Type",
+            "application/json; charset=utf-8",
+            false
+          );
+          setCacheHeaders();
+          response.write('{ "greeting": "Hello JSON!" }');
+          response.finish();
+          break;
+        }
+
+        case "font": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "font/woff", false);
+          setCacheHeaders();
+          response.finish();
+          break;
+        }
+        case "image": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "image/png", false);
+          setCacheHeaders();
+          response.finish();
+          break;
+        }
+        case "application-ogg": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "application/ogg", false);
+          setCacheHeaders();
+          response.finish();
+          break;
+        }
+        case "audio": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "audio/ogg", false);
+          setCacheHeaders();
+          response.finish();
+          break;
+        }
+        case "video": {
+          response.setStatusLine(request.httpVersion, status, "OK");
+          response.setHeader("Content-Type", "video/webm", false);
+          setCacheHeaders();
+          response.finish();
+          break;
+        }
+        case "ws": {
+          response.setStatusLine(
+            request.httpVersion,
+            101,
+            "Switching Protocols"
+          );
+          response.setHeader("Connection", "upgrade", false);
+          response.setHeader("Upgrade", "websocket", false);
+          setCacheHeaders();
+          response.finish();
+          break;
+        }
+        default: {
+          response.setStatusLine(request.httpVersion, 404, "Not Found");
+          response.setHeader("Content-Type", "text/html; charset=utf-8", false);
+          setCacheHeaders();
+          response.write("<blink>Not Found</blink>");
+          response.finish();
+          break;
+        }
+      }
+    },
+    10,
+    Ci.nsITimer.TYPE_ONE_SHOT
+  ); // Make sure this request takes a few ms.
+}