Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

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

12 files changed, 1078 insertions, 0 deletions

diff --git a/browser/extensions/search-detection/extension/api.js b/browser/extensions/search-detection/extension/api.js
new file mode 100644
index 0000000000..873a2ecedd
--- /dev/null
+++ b/browser/extensions/search-detection/extension/api.js
@@ -0,0 +1,264 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global ExtensionCommon, ExtensionAPI, Services, XPCOMUtils, ExtensionUtils */
+
+const { AddonManager } = ChromeUtils.importESModule(
+  "resource://gre/modules/AddonManager.sys.mjs"
+);
+const { WebRequest } = ChromeUtils.importESModule(
+  "resource://gre/modules/WebRequest.sys.mjs"
+);
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  AddonSearchEngine: "resource://gre/modules/AddonSearchEngine.sys.mjs",
+});
+
+// eslint-disable-next-line mozilla/reject-importGlobalProperties
+XPCOMUtils.defineLazyGlobalGetters(this, ["ChannelWrapper"]);
+
+XPCOMUtils.defineLazyGetter(this, "searchInitialized", () => {
+  if (Services.search.isInitialized) {
+    return Promise.resolve();
+  }
+
+  return ExtensionUtils.promiseObserved(
+    "browser-search-service",
+    (_, data) => data === "init-complete"
+  );
+});
+
+const SEARCH_TOPIC_ENGINE_MODIFIED = "browser-search-engine-modified";
+
+this.addonsSearchDetection = class extends ExtensionAPI {
+  getAPI(context) {
+    const { extension } = context;
+
+    // We want to temporarily store the first monitored URLs that have been
+    // redirected, indexed by request IDs, so that the background script can
+    // find the add-on IDs to report.
+    this.firstMatchedUrls = {};
+
+    return {
+      addonsSearchDetection: {
+        // `getMatchPatterns()` returns a map where each key is an URL pattern
+        // to monitor and its corresponding value is a list of add-on IDs
+        // (search engines).
+        //
+        // Note: We don't return a simple list of URL patterns because the
+        // background script might want to lookup add-on IDs for a given URL in
+        // the case of server-side redirects.
+        async getMatchPatterns() {
+          const patterns = {};
+
+          try {
+            await searchInitialized;
+            const visibleEngines = await Services.search.getEngines();
+
+            visibleEngines.forEach(engine => {
+              if (!(engine instanceof lazy.AddonSearchEngine)) {
+                return;
+              }
+              const { _extensionID, _urls } = engine.wrappedJSObject;
+
+              if (!_extensionID) {
+                // OpenSearch engines don't have an extension ID.
+                return;
+              }
+
+              _urls
+                // We only want to collect "search URLs" (and not "suggestion"
+                // ones for instance). See `URL_TYPE` in `SearchUtils.jsm`.
+                .filter(({ type }) => type === "text/html")
+                .forEach(({ template }) => {
+                  // If this is changed, double check the code in the background
+                  // script because `webRequestCancelledHandler` splits patterns
+                  // on `*` to retrieve URL prefixes.
+                  const pattern = template.split("?")[0] + "*";
+
+                  // Multiple search engines could register URL templates that
+                  // would become the same URL pattern as defined above so we
+                  // store a list of extension IDs per URL pattern.
+                  if (!patterns[pattern]) {
+                    patterns[pattern] = [];
+                  }
+
+                  // We exclude built-in search engines because we don't need
+                  // to report them.
+                  if (
+                    !patterns[pattern].includes(_extensionID) &&
+                    !_extensionID.endsWith("@search.mozilla.org")
+                  ) {
+                    patterns[pattern].push(_extensionID);
+                  }
+                });
+            });
+          } catch (err) {
+            console.error(err);
+          }
+
+          return patterns;
+        },
+
+        // `getAddonVersion()` returns the add-on version if it exists.
+        async getAddonVersion(addonId) {
+          const addon = await AddonManager.getAddonByID(addonId);
+
+          return addon && addon.version;
+        },
+
+        // `getPublicSuffix()` returns the public suffix/Effective TLD Service
+        // of the given URL.
+        // See: https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Reference/Interface/nsIEffectiveTLDService
+        async getPublicSuffix(url) {
+          try {
+            return Services.eTLD.getBaseDomain(Services.io.newURI(url));
+          } catch (err) {
+            console.error(err);
+            return null;
+          }
+        },
+
+        // `onSearchEngineModified` is an event that occurs when the list of
+        // search engines has changed, e.g., a new engine has been added or an
+        // engine has been removed.
+        //
+        // See: https://searchfox.org/mozilla-central/source/toolkit/components/search/SearchUtils.jsm#145-152
+        onSearchEngineModified: new ExtensionCommon.EventManager({
+          context,
+          name: "addonsSearchDetection.onSearchEngineModified",
+          register: fire => {
+            const onSearchEngineModifiedObserver = (
+              aSubject,
+              aTopic,
+              aData
+            ) => {
+              if (
+                aTopic !== SEARCH_TOPIC_ENGINE_MODIFIED ||
+                // We are only interested in these modified types.
+                !["engine-added", "engine-removed", "engine-changed"].includes(
+                  aData
+                )
+              ) {
+                return;
+              }
+
+              fire.async();
+            };
+
+            Services.obs.addObserver(
+              onSearchEngineModifiedObserver,
+              SEARCH_TOPIC_ENGINE_MODIFIED
+            );
+
+            return () => {
+              Services.obs.removeObserver(
+                onSearchEngineModifiedObserver,
+                SEARCH_TOPIC_ENGINE_MODIFIED
+              );
+            };
+          },
+        }).api(),
+
+        // `onRedirected` is an event fired after a request has stopped and
+        // this request has been redirected once or more. The registered
+        // listeners will received the following properties:
+        //
+        //   - `addonId`: the add-on ID that redirected the request, if any.
+        //   - `firstUrl`: the first monitored URL of the request that has
+        //      been redirected.
+        //   - `lastUrl`: the last URL loaded for the request, after one or
+        //      more redirects.
+        onRedirected: new ExtensionCommon.EventManager({
+          context,
+          name: "addonsSearchDetection.onRedirected",
+          register: (fire, filter) => {
+            const stopListener = event => {
+              if (event.type != "stop") {
+                return;
+              }
+
+              const wrapper = event.currentTarget;
+              const { channel, id: requestId } = wrapper;
+
+              // When we detected a redirect, we read the request property,
+              // hoping to find an add-on ID corresponding to the add-on that
+              // initiated the redirect. It might not return anything when the
+              // redirect is a search server-side redirect but it can also be
+              // caused by an error.
+              let addonId;
+              try {
+                addonId = channel
+                  ?.QueryInterface(Ci.nsIPropertyBag)
+                  ?.getProperty("redirectedByExtension");
+              } catch (err) {
+                console.error(err);
+              }
+
+              const firstUrl = this.firstMatchedUrls[requestId];
+              // We don't need this entry anymore.
+              delete this.firstMatchedUrls[requestId];
+
+              const lastUrl = wrapper.finalURL;
+
+              if (!firstUrl || !lastUrl) {
+                // Something went wrong but there is nothing we can do at this
+                // point.
+                return;
+              }
+
+              fire.sync({ addonId, firstUrl, lastUrl });
+            };
+
+            const listener = ({ requestId, url, originUrl }) => {
+              // We exclude requests not originating from the location bar,
+              // bookmarks and other "system-ish" requests.
+              if (originUrl !== undefined) {
+                return;
+              }
+
+              // Keep the first monitored URL that was redirected for the
+              // request until the request has stopped.
+              if (!this.firstMatchedUrls[requestId]) {
+                this.firstMatchedUrls[requestId] = url;
+
+                const wrapper = ChannelWrapper.getRegisteredChannel(
+                  requestId,
+                  context.extension.policy,
+                  context.xulBrowser.frameLoader.remoteTab
+                );
+
+                wrapper.addEventListener("stop", stopListener);
+              }
+            };
+
+            WebRequest.onBeforeRedirect.addListener(
+              listener,
+              // filter
+              {
+                types: ["main_frame"],
+                urls: ExtensionUtils.parseMatchPatterns(filter.urls),
+              },
+              // info
+              [],
+              // listener details
+              {
+                addonId: extension.id,
+                policy: extension.policy,
+                blockingAllowed: false,
+              }
+            );
+
+            return () => {
+              WebRequest.onBeforeRedirect.removeListener(listener);
+            };
+          },
+        }).api(),
+      },
+    };
+  }
+};
diff --git a/browser/extensions/search-detection/extension/background.js b/browser/extensions/search-detection/extension/background.js
new file mode 100644
index 0000000000..043bb0243f
--- /dev/null
+++ b/browser/extensions/search-detection/extension/background.js
@@ -0,0 +1,178 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global browser */
+
+const TELEMETRY_CATEGORY = "addonsSearchDetection";
+// methods
+const TELEMETRY_METHOD_ETLD_CHANGE = "etld_change";
+// objects
+const TELEMETRY_OBJECT_WEBREQUEST = "webrequest";
+const TELEMETRY_OBJECT_OTHER = "other";
+// values
+const TELEMETRY_VALUE_EXTENSION = "extension";
+const TELEMETRY_VALUE_SERVER = "server";
+
+class AddonsSearchDetection {
+  constructor() {
+    // The key is an URL pattern to monitor and its corresponding value is a
+    // list of add-on IDs.
+    this.matchPatterns = {};
+
+    browser.telemetry.registerEvents(TELEMETRY_CATEGORY, {
+      [TELEMETRY_METHOD_ETLD_CHANGE]: {
+        methods: [TELEMETRY_METHOD_ETLD_CHANGE],
+        objects: [TELEMETRY_OBJECT_WEBREQUEST, TELEMETRY_OBJECT_OTHER],
+        extra_keys: ["addonId", "addonVersion", "from", "to"],
+        record_on_release: true,
+      },
+    });
+
+    this.onRedirectedListener = this.onRedirectedListener.bind(this);
+  }
+
+  async getMatchPatterns() {
+    try {
+      this.matchPatterns =
+        await browser.addonsSearchDetection.getMatchPatterns();
+    } catch (err) {
+      console.error(`failed to retrieve the list of URL patterns: ${err}`);
+      this.matchPatterns = {};
+    }
+
+    return this.matchPatterns;
+  }
+
+  // When the search service changes the set of engines that are enabled, we
+  // update our pattern matching in the webrequest listeners (go to the bottom
+  // of this file for the search service events we listen to).
+  async monitor() {
+    // If there is already a listener, remove it so that we can re-add one
+    // after. This is because we're using the same listener with different URL
+    // patterns (when the list of search engines changes).
+    if (
+      browser.addonsSearchDetection.onRedirected.hasListener(
+        this.onRedirectedListener
+      )
+    ) {
+      browser.addonsSearchDetection.onRedirected.removeListener(
+        this.onRedirectedListener
+      );
+    }
+    // If there is already a listener, remove it so that we can re-add one
+    // after. This is because we're using the same listener with different URL
+    // patterns (when the list of search engines changes).
+    if (browser.webRequest.onBeforeRequest.hasListener(this.noOpListener)) {
+      browser.webRequest.onBeforeRequest.removeListener(this.noOpListener);
+    }
+
+    // Retrieve the list of URL patterns to monitor with our listener.
+    //
+    // Note: search suggestions are system principal requests, so webRequest
+    // cannot intercept them.
+    const matchPatterns = await this.getMatchPatterns();
+    const patterns = Object.keys(matchPatterns);
+
+    if (patterns.length === 0) {
+      return;
+    }
+
+    browser.webRequest.onBeforeRequest.addListener(
+      this.noOpListener,
+      { types: ["main_frame"], urls: patterns },
+      ["blocking"]
+    );
+
+    browser.addonsSearchDetection.onRedirected.addListener(
+      this.onRedirectedListener,
+      { urls: patterns }
+    );
+  }
+
+  // This listener is required to force the registration of traceable channels.
+  noOpListener() {
+    // Do nothing.
+  }
+
+  async onRedirectedListener({ addonId, firstUrl, lastUrl }) {
+    // When we do not have an add-on ID (in the request property bag), we
+    // likely detected a search server-side redirect.
+    const maybeServerSideRedirect = !addonId;
+
+    let addonIds = [];
+    // Search server-side redirects are possible because an extension has
+    // registered a search engine, which is why we can (hopefully) retrieve the
+    // add-on ID.
+    if (maybeServerSideRedirect) {
+      addonIds = this.getAddonIdsForUrl(firstUrl);
+    } else if (addonId) {
+      addonIds = [addonId];
+    }
+
+    if (addonIds.length === 0) {
+      // No add-on ID means there is nothing we can report.
+      return;
+    }
+
+    // This is the monitored URL that was first redirected.
+    const from = await browser.addonsSearchDetection.getPublicSuffix(firstUrl);
+    // This is the final URL after redirect(s).
+    const to = await browser.addonsSearchDetection.getPublicSuffix(lastUrl);
+
+    if (from === to) {
+      // We do not want to report redirects to same public suffixes. However,
+      // we will report redirects from public suffixes belonging to a same
+      // entity (.e.g., `example.com` -> `example.fr`).
+      //
+      // Known limitation: if a redirect chain starts and ends with the same
+      // public suffix, we won't report any event, even if the chain contains
+      // different public suffixes in between.
+      return;
+    }
+
+    const telemetryObject = maybeServerSideRedirect
+      ? TELEMETRY_OBJECT_OTHER
+      : TELEMETRY_OBJECT_WEBREQUEST;
+    const telemetryValue = maybeServerSideRedirect
+      ? TELEMETRY_VALUE_SERVER
+      : TELEMETRY_VALUE_EXTENSION;
+
+    for (const id of addonIds) {
+      const addonVersion = await browser.addonsSearchDetection.getAddonVersion(
+        id
+      );
+      const extra = { addonId: id, addonVersion, from, to };
+
+      browser.telemetry.recordEvent(
+        TELEMETRY_CATEGORY,
+        TELEMETRY_METHOD_ETLD_CHANGE,
+        telemetryObject,
+        telemetryValue,
+        extra
+      );
+    }
+  }
+
+  getAddonIdsForUrl(url) {
+    for (const pattern of Object.keys(this.matchPatterns)) {
+      // `getMatchPatterns()` returns the prefix plus "*".
+      const urlPrefix = pattern.slice(0, -1);
+
+      if (url.startsWith(urlPrefix)) {
+        return this.matchPatterns[pattern];
+      }
+    }
+
+    return [];
+  }
+}
+
+const exp = new AddonsSearchDetection();
+exp.monitor();
+
+browser.addonsSearchDetection.onSearchEngineModified.addListener(async () => {
+  await exp.monitor();
+});
diff --git a/browser/extensions/search-detection/extension/manifest.json b/browser/extensions/search-detection/extension/manifest.json
new file mode 100644
index 0000000000..bbfa304654
--- /dev/null
+++ b/browser/extensions/search-detection/extension/manifest.json
@@ -0,0 +1,32 @@
+{
+  "manifest_version": 2,
+  "name": "Add-ons Search Detection",
+  "hidden": true,
+  "browser_specific_settings": {
+    "gecko": {
+      "id": "addons-search-detection@mozilla.com"
+    }
+  },
+  "version": "2.0.0",
+  "description": "",
+  "experiment_apis": {
+    "addonsSearchDetection": {
+      "schema": "schema.json",
+      "parent": {
+        "scopes": ["addon_parent"],
+        "script": "api.js",
+        "events": [],
+        "paths": [["addonsSearchDetection"]]
+      }
+    }
+  },
+  "permissions": [
+    "<all_urls>",
+    "telemetry",
+    "webRequest",
+    "webRequestBlocking"
+  ],
+  "background": {
+    "scripts": ["background.js"]
+  }
+}
diff --git a/browser/extensions/search-detection/extension/schema.json b/browser/extensions/search-detection/extension/schema.json
new file mode 100644
index 0000000000..e3c77e3f3d
--- /dev/null
+++ b/browser/extensions/search-detection/extension/schema.json
@@ -0,0 +1,60 @@
+[
+  {
+    "namespace": "addonsSearchDetection",
+    "functions": [
+      {
+        "name": "getMatchPatterns",
+        "type": "function",
+        "async": true,
+        "parameters": []
+      },
+      {
+        "name": "getAddonVersion",
+        "type": "function",
+        "async": true,
+        "parameters": [{ "name": "addonId", "type": "string" }]
+      },
+      {
+        "name": "getPublicSuffix",
+        "type": "function",
+        "async": true,
+        "parameters": [{ "name": "url", "type": "string" }]
+      }
+    ],
+    "events": [
+      {
+        "name": "onSearchEngineModified",
+        "type": "function",
+        "parameters": []
+      },
+      {
+        "name": "onRedirected",
+        "type": "function",
+        "parameters": [
+          {
+            "name": "details",
+            "type": "object",
+            "properties": {
+              "addonId": { "type": "string" },
+              "firstUrl": { "type": "string" },
+              "lastUrl": { "type": "string" }
+            }
+          }
+        ],
+        "extraParameters": [
+          {
+            "name": "filter",
+            "type": "object",
+            "properties": {
+              "urls": {
+                "type": "array",
+                "items": { "type": "string" },
+                "minItems": 1
+              }
+            }
+          }
+        ]
+      }
+    ]
+  }
+]
diff --git a/browser/extensions/search-detection/jar.mn b/browser/extensions/search-detection/jar.mn
new file mode 100644
index 0000000000..377c2be080
--- /dev/null
+++ b/browser/extensions/search-detection/jar.mn
@@ -0,0 +1,7 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+browser.jar:
+%   resource builtin-addons %builtin-addons/  contentaccessible=yes
+    builtin-addons/search-detection/ (extension/**)
diff --git a/browser/extensions/search-detection/moz.build b/browser/extensions/search-detection/moz.build
new file mode 100644
index 0000000000..7aa40597b1
--- /dev/null
+++ b/browser/extensions/search-detection/moz.build
@@ -0,0 +1,10 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+JAR_MANIFESTS += ["jar.mn"]
+
+BROWSER_CHROME_MANIFESTS += ["tests/browser/browser.ini"]
+
+with Files("**"):
+    BUG_COMPONENT = ("WebExtensions", "General")
diff --git a/browser/extensions/search-detection/tests/browser/.eslintrc.js b/browser/extensions/search-detection/tests/browser/.eslintrc.js
new file mode 100644
index 0000000000..e57058ecb1
--- /dev/null
+++ b/browser/extensions/search-detection/tests/browser/.eslintrc.js
@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = {
+  env: {
+    webextensions: true,
+  },
+};
diff --git a/browser/extensions/search-detection/tests/browser/browser.ini b/browser/extensions/search-detection/tests/browser/browser.ini
new file mode 100644
index 0000000000..1bd22fe386
--- /dev/null
+++ b/browser/extensions/search-detection/tests/browser/browser.ini
@@ -0,0 +1,9 @@
+[DEFAULT]
+support-files =
+  redirect.sjs
+
+[browser_client_side_redirection.js]
+[browser_extension_loaded.js]
+[browser_server_side_redirection.js]
+skip-if =
+  os == "win" && os_version == "6.1" # Skip on Azure - frequent failure
diff --git a/browser/extensions/search-detection/tests/browser/browser_client_side_redirection.js b/browser/extensions/search-detection/tests/browser/browser_client_side_redirection.js
new file mode 100644
index 0000000000..5dad39dba4
--- /dev/null
+++ b/browser/extensions/search-detection/tests/browser/browser_client_side_redirection.js
@@ -0,0 +1,204 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { AddonTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/AddonTestUtils.sys.mjs"
+);
+
+const { TelemetryTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/TelemetryTestUtils.sys.mjs"
+);
+
+AddonTestUtils.initMochitest(this);
+
+const TELEMETRY_EVENTS_FILTERS = {
+  category: "addonsSearchDetection",
+  method: "etld_change",
+};
+
+// The search-detection built-in add-on registers dynamic events.
+const TELEMETRY_TEST_UTILS_OPTIONS = { clear: true, process: "dynamic" };
+
+async function testClientSideRedirect({
+  background,
+  permissions,
+  telemetryExpected = false,
+}) {
+  Services.telemetry.clearEvents();
+
+  // Load an extension that does a client-side redirect. We expect this
+  // extension to be reported in a Telemetry event when `telemetryExpected` is
+  // set to `true`.
+  const addonId = "some@addon-id";
+  const addonVersion = "1.2.3";
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      version: addonVersion,
+      browser_specific_settings: { gecko: { id: addonId } },
+      permissions,
+    },
+    useAddonManager: "temporary",
+    background,
+  });
+
+  await extension.startup();
+  await extension.awaitMessage("ready");
+
+  // Simulate a search (with the test search engine) by navigating to it.
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: "https://example.com/search?q=babar",
+    },
+    () => {}
+  );
+
+  await extension.unload();
+
+  TelemetryTestUtils.assertEvents(
+    telemetryExpected
+      ? [
+          {
+            object: "webrequest",
+            value: "extension",
+            extra: {
+              addonId,
+              addonVersion,
+              from: "example.com",
+              to: "mochi.test",
+            },
+          },
+        ]
+      : [],
+    TELEMETRY_EVENTS_FILTERS,
+    TELEMETRY_TEST_UTILS_OPTIONS
+  );
+}
+
+add_setup(async function () {
+  const searchEngineName = "test search engine";
+
+  let searchEngine;
+
+  // This cleanup function has to be registered before the one registered
+  // internally by loadExtension, otherwise it is going to trigger a test
+  // failure (because it will be called too late).
+  registerCleanupFunction(async () => {
+    await searchEngine.unload();
+    ok(
+      !Services.search.getEngineByName(searchEngineName),
+      "test search engine unregistered"
+    );
+  });
+
+  searchEngine = ExtensionTestUtils.loadExtension({
+    manifest: {
+      chrome_settings_overrides: {
+        search_provider: {
+          name: searchEngineName,
+          keyword: "test",
+          search_url: "https://example.com/?q={searchTerms}",
+        },
+      },
+    },
+    // NOTE: the search extension needs to be installed through the
+    // AddonManager to be correctly unregistered when it is uninstalled.
+    useAddonManager: "temporary",
+  });
+
+  await searchEngine.startup();
+  await AddonTestUtils.waitForSearchProviderStartup(searchEngine);
+  ok(
+    Services.search.getEngineByName(searchEngineName),
+    "test search engine registered"
+  );
+});
+
+add_task(function test_onBeforeRequest() {
+  return testClientSideRedirect({
+    background() {
+      browser.webRequest.onBeforeRequest.addListener(
+        () => {
+          return {
+            redirectUrl: "http://mochi.test:8888/",
+          };
+        },
+        { urls: ["*://example.com/*"] },
+        ["blocking"]
+      );
+
+      browser.test.sendMessage("ready");
+    },
+    permissions: ["webRequest", "webRequestBlocking", "*://example.com/*"],
+    telemetryExpected: true,
+  });
+});
+
+add_task(function test_onBeforeRequest_url_not_monitored() {
+  // Here, we load an extension that does a client-side redirect. Because this
+  // extension does not listen to the URL of the search engine registered
+  // above, we don't expect this extension to be reported in a Telemetry event.
+  return testClientSideRedirect({
+    background() {
+      browser.webRequest.onBeforeRequest.addListener(
+        () => {
+          return {
+            redirectUrl: "http://mochi.test:8888/",
+          };
+        },
+        { urls: ["*://google.com/*"] },
+        ["blocking"]
+      );
+
+      browser.test.sendMessage("ready");
+    },
+    permissions: ["webRequest", "webRequestBlocking", "*://google.com/*"],
+    telemetryExpected: false,
+  });
+});
+
+add_task(function test_onHeadersReceived() {
+  return testClientSideRedirect({
+    background() {
+      browser.webRequest.onHeadersReceived.addListener(
+        () => {
+          return {
+            redirectUrl: "http://mochi.test:8888/",
+          };
+        },
+        { urls: ["*://example.com/*"], types: ["main_frame"] },
+        ["blocking"]
+      );
+
+      browser.test.sendMessage("ready");
+    },
+    permissions: ["webRequest", "webRequestBlocking", "*://example.com/*"],
+    telemetryExpected: true,
+  });
+});
+
+add_task(function test_onHeadersReceived_url_not_monitored() {
+  // Here, we load an extension that does a client-side redirect. Because this
+  // extension does not listen to the URL of the search engine registered
+  // above, we don't expect this extension to be reported in a Telemetry event.
+  return testClientSideRedirect({
+    background() {
+      browser.webRequest.onHeadersReceived.addListener(
+        () => {
+          return {
+            redirectUrl: "http://mochi.test:8888/",
+          };
+        },
+        { urls: ["*://google.com/*"], types: ["main_frame"] },
+        ["blocking"]
+      );
+
+      browser.test.sendMessage("ready");
+    },
+    permissions: ["webRequest", "webRequestBlocking", "*://google.com/*"],
+    telemetryExpected: false,
+  });
+});
diff --git a/browser/extensions/search-detection/tests/browser/browser_extension_loaded.js b/browser/extensions/search-detection/tests/browser/browser_extension_loaded.js
new file mode 100644
index 0000000000..65f6ed09a8
--- /dev/null
+++ b/browser/extensions/search-detection/tests/browser/browser_extension_loaded.js
@@ -0,0 +1,15 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_searchDetection_isActive() {
+  let addon = await AddonManager.getAddonByID(
+    "addons-search-detection@mozilla.com"
+  );
+
+  ok(addon, "Add-on exists");
+  ok(addon.isActive, "Add-on is active");
+  ok(addon.isBuiltin, "Add-on is built-in");
+  ok(addon.hidden, "Add-on is hidden");
+});
diff --git a/browser/extensions/search-detection/tests/browser/browser_server_side_redirection.js b/browser/extensions/search-detection/tests/browser/browser_server_side_redirection.js
new file mode 100644
index 0000000000..ea235406a4
--- /dev/null
+++ b/browser/extensions/search-detection/tests/browser/browser_server_side_redirection.js
@@ -0,0 +1,260 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { AddonTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/AddonTestUtils.sys.mjs"
+);
+
+const { TelemetryTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/TelemetryTestUtils.sys.mjs"
+);
+
+AddonTestUtils.initMochitest(this);
+
+const TELEMETRY_EVENTS_FILTERS = {
+  category: "addonsSearchDetection",
+  method: "etld_change",
+};
+
+// The search-detection built-in add-on registers dynamic events.
+const TELEMETRY_TEST_UTILS_OPTIONS = { clear: true, process: "dynamic" };
+
+const REDIRECT_SJS =
+  "browser/browser/extensions/search-detection/tests/browser/redirect.sjs?q={searchTerms}";
+// This URL will redirect to `example.net`, which is different than
+// `*.example.com`. That will be the final URL of a redirect chain:
+// www.example.com -> example.net
+const SEARCH_URL_WWW = `https://www.example.com/${REDIRECT_SJS}`;
+// This URL will redirect to `www.example.com`, which will create a redirect
+// chain with two hops:
+// test2.example.com -> www.example.com -> example.net
+const SEARCH_URL_TEST2 = `https://test2.example.com/${REDIRECT_SJS}`;
+// This URL will redirect to `test2.example.com`, which will create a redirect
+// chain with three hops:
+// test1.example.com -> test2.example.com -> www.example.com -> example.net
+const SEARCH_URL_TEST1 = `https://test1.example.com/${REDIRECT_SJS}`;
+
+const TEST_SEARCH_ENGINE_ADDON_ID = "some@addon-id";
+const TEST_SEARCH_ENGINE_ADDON_VERSION = "4.5.6";
+
+const testServerSideRedirect = async ({
+  searchURL,
+  expectedEvents,
+  tabURL,
+}) => {
+  Services.telemetry.clearEvents();
+
+  const searchEngineName = "test search engine";
+  // Load a default search engine because the add-on we are testing here
+  // monitors the search engines.
+  const searchEngine = ExtensionTestUtils.loadExtension({
+    manifest: {
+      version: TEST_SEARCH_ENGINE_ADDON_VERSION,
+      browser_specific_settings: {
+        gecko: { id: TEST_SEARCH_ENGINE_ADDON_ID },
+      },
+      chrome_settings_overrides: {
+        search_provider: {
+          name: searchEngineName,
+          keyword: "test",
+          search_url: searchURL,
+        },
+      },
+    },
+    useAddonManager: "temporary",
+  });
+
+  await searchEngine.startup();
+  ok(
+    Services.search.getEngineByName(searchEngineName),
+    "test search engine registered"
+  );
+  await AddonTestUtils.waitForSearchProviderStartup(searchEngine);
+
+  // Simulate a search (with the test search engine) by navigating to it.
+  const url = tabURL || searchURL.replace("{searchTerms}", "some terms");
+  await BrowserTestUtils.withNewTab("about:blank", async browser => {
+    // Wait for the tab to be fully loaded.
+    let loaded = BrowserTestUtils.browserLoaded(browser);
+    BrowserTestUtils.loadURIString(browser, url);
+    await loaded;
+  });
+
+  await searchEngine.unload();
+  ok(
+    !Services.search.getEngineByName(searchEngineName),
+    "test search engine unregistered"
+  );
+
+  TelemetryTestUtils.assertEvents(
+    expectedEvents,
+    TELEMETRY_EVENTS_FILTERS,
+    TELEMETRY_TEST_UTILS_OPTIONS
+  );
+};
+
+add_task(function test_redirect_final() {
+  return testServerSideRedirect({
+    // www.example.com -> example.net
+    searchURL: SEARCH_URL_WWW,
+    expectedEvents: [
+      {
+        object: "other",
+        value: "server",
+        extra: {
+          addonId: TEST_SEARCH_ENGINE_ADDON_ID,
+          addonVersion: TEST_SEARCH_ENGINE_ADDON_VERSION,
+          from: "example.com",
+          to: "example.net",
+        },
+      },
+    ],
+  });
+});
+
+add_task(function test_redirect_two_hops() {
+  return testServerSideRedirect({
+    // test2.example.com -> www.example.com -> example.net
+    searchURL: SEARCH_URL_TEST2,
+    expectedEvents: [
+      {
+        object: "other",
+        value: "server",
+        extra: {
+          addonId: TEST_SEARCH_ENGINE_ADDON_ID,
+          addonVersion: TEST_SEARCH_ENGINE_ADDON_VERSION,
+          from: "example.com",
+          to: "example.net",
+        },
+      },
+    ],
+  });
+});
+
+add_task(function test_redirect_three_hops() {
+  return testServerSideRedirect({
+    // test1.example.com -> test2.example.com -> www.example.com -> example.net
+    searchURL: SEARCH_URL_TEST1,
+    expectedEvents: [
+      {
+        object: "other",
+        value: "server",
+        extra: {
+          addonId: TEST_SEARCH_ENGINE_ADDON_ID,
+          addonVersion: TEST_SEARCH_ENGINE_ADDON_VERSION,
+          from: "example.com",
+          to: "example.net",
+        },
+      },
+    ],
+  });
+});
+
+add_task(function test_no_event_when_search_engine_not_used() {
+  return testServerSideRedirect({
+    // www.example.com -> example.net
+    searchURL: SEARCH_URL_WWW,
+    // We do not expect any events because the user is not using the search
+    // engine that was registered.
+    tabURL: "http://mochi.test:8888/search?q=foobar",
+    expectedEvents: [],
+  });
+});
+
+add_task(function test_redirect_chain_does_not_start_on_first_request() {
+  return testServerSideRedirect({
+    // www.example.com -> example.net
+    searchURL: SEARCH_URL_WWW,
+    // User first navigates to an URL that isn't monitored and will be
+    // redirected to another URL that is monitored.
+    tabURL: `http://mochi.test:8888/browser/browser/extensions/search-detection/tests/browser/redirect.sjs?q={searchTerms}`,
+    expectedEvents: [
+      {
+        object: "other",
+        value: "server",
+        extra: {
+          addonId: TEST_SEARCH_ENGINE_ADDON_ID,
+          addonVersion: TEST_SEARCH_ENGINE_ADDON_VERSION,
+          // We expect this and not `mochi.test` because we do not monitor
+          // `mochi.test`, only `example.com`, which is coming from the search
+          // engine registered in the test setup.
+          from: "example.com",
+          to: "example.net",
+        },
+      },
+    ],
+  });
+});
+
+add_task(async function test_two_extensions_reported() {
+  Services.telemetry.clearEvents();
+
+  const searchEngines = [];
+  for (const [addonId, addonVersion, isDefault] of [
+    ["1-addon@guid", "1.2", false],
+    ["2-addon@guid", "3.4", true],
+  ]) {
+    const searchEngine = ExtensionTestUtils.loadExtension({
+      manifest: {
+        version: addonVersion,
+        browser_specific_settings: {
+          gecko: { id: addonId },
+        },
+        chrome_settings_overrides: {
+          search_provider: {
+            is_default: isDefault,
+            name: `test search engine - ${addonId}`,
+            keyword: "test",
+            search_url: `${SEARCH_URL_WWW}&id=${addonId}`,
+          },
+        },
+      },
+      useAddonManager: "temporary",
+    });
+
+    await searchEngine.startup();
+    await AddonTestUtils.waitForSearchProviderStartup(searchEngine);
+
+    searchEngines.push(searchEngine);
+  }
+
+  // Simulate a search by navigating to it.
+  const url = SEARCH_URL_WWW.replace("{searchTerms}", "some terms");
+  await BrowserTestUtils.withNewTab("about:blank", async browser => {
+    // Wait for the tab to be fully loaded.
+    let loaded = BrowserTestUtils.browserLoaded(browser);
+    BrowserTestUtils.loadURIString(browser, url);
+    await loaded;
+  });
+
+  await Promise.all(searchEngines.map(engine => engine.unload()));
+
+  TelemetryTestUtils.assertEvents(
+    [
+      {
+        object: "other",
+        value: "server",
+        extra: {
+          addonId: "1-addon@guid",
+          addonVersion: "1.2",
+          from: "example.com",
+          to: "example.net",
+        },
+      },
+      {
+        object: "other",
+        value: "server",
+        extra: {
+          addonId: "2-addon@guid",
+          addonVersion: "3.4",
+          from: "example.com",
+          to: "example.net",
+        },
+      },
+    ],
+    TELEMETRY_EVENTS_FILTERS,
+    TELEMETRY_TEST_UTILS_OPTIONS
+  );
+});
diff --git a/browser/extensions/search-detection/tests/browser/redirect.sjs b/browser/extensions/search-detection/tests/browser/redirect.sjs
new file mode 100644
index 0000000000..27cb29b32e
--- /dev/null
+++ b/browser/extensions/search-detection/tests/browser/redirect.sjs
@@ -0,0 +1,32 @@
+const REDIRECT_SJS =
+  "browser/browser/extensions/search-detection/tests/browser/redirect.sjs";
+
+// This handler is used to create redirect chains with multiple sub-domains,
+// and the next hop is defined by the current `host`.
+function handleRequest(request, response) {
+  let newLocation;
+
+  // test1.example.com -> test2.example.com -> www.example.com -> example.net
+  switch (request.host) {
+    case "test1.example.com":
+      newLocation = `https://test2.example.com/${REDIRECT_SJS}`;
+      break;
+    case "test2.example.com":
+      newLocation = `https://www.example.com/${REDIRECT_SJS}`;
+      break;
+    case "www.example.com":
+      newLocation = "https://example.net/";
+      break;
+    // We redirect `mochi.test` to `www` in
+    // `test_redirect_chain_does_not_start_on_first_request()`.
+    case "mochi.test":
+      newLocation = `https://www.example.com/${REDIRECT_SJS}`;
+      break;
+    default:
+      // Redirect to a different website in case of unexpected events.
+      newLocation = "https://mozilla.org/";
+  }
+
+  response.setStatusLine(request.httpVersion, 302, "Found");
+  response.setHeader("Location", newLocation);
+}