diff --git a/addons/bus/static/tests/helpers/mock_server.js b/addons/bus/static/tests/helpers/mock_server.js
new file mode 100644
index 00000000000..7ee17261cee
--- /dev/null
+++ b/addons/bus/static/tests/helpers/mock_server.js
@@ -0,0 +1,62 @@
+/** @odoo-module **/
+
+import { patch } from "@web/core/utils/patch";
+import { MockServer } from "@web/../tests/helpers/mock_server";
+import { makeDeferred } from "@web/../tests/helpers/utils";
+
+patch(MockServer.prototype, 'bus', {
+    init() {
+        this._super(...arguments);
+        this.pendingLongpollingPromise = null;
+        this.notificationsToBeResolved = [];
+    },
+
+    //--------------------------------------------------------------------------
+    // Private
+    //--------------------------------------------------------------------------
+
+    /**
+     * @override
+     */
+    async _performRPC(route, args) {
+        if (route === '/longpolling/poll') {
+            const longpollingPromise = makeDeferred();
+            if (this.notificationsToBeResolved.length) {
+                longpollingPromise.resolve(this.notificationsToBeResolved);
+                this.notificationsToBeResolved = [];
+            } else {
+                this.pendingLongpollingPromise = longpollingPromise;
+            }
+            return longpollingPromise;
+        }
+        return this._super(route, args);
+    },
+    /**
+     * Simulates `_sendone` on `bus.bus`.
+     *
+     * @param {string} channel
+     * @param {string} notificationType
+     * @param {any} message
+     */
+    _mockBusBus__sendone(channel, notificationType, message) {
+       this._mockBusBus__sendmany([[channel, notificationType, message]]);
+    },
+    /**
+     * Simulates `_sendmany` on `bus.bus`.
+     *
+     * @param {Array} notifications
+     */
+    _mockBusBus__sendmany(notifications) {
+        const values = [];
+        for (const notification of notifications) {
+            const [type, payload] = notification.slice(1, notification.length);
+            values.push({ message: { payload, type } });
+        }
+        if (this.pendingLongpollingPromise) {
+            this.pendingLongpollingPromise.resolve(values);
+            this.pendingLongpollingPromise = null;
+        } else {
+            this.notificationsToBeResolved.push(...values);
+        }
+    },
+});
diff --git a/addons/mail/static/tests/helpers/mock_server.js b/addons/mail/static/tests/helpers/mock_server.js
index 4e758195002..568df1cb6e4 100644
--- a/addons/mail/static/tests/helpers/mock_server.js
+++ b/addons/mail/static/tests/helpers/mock_server.js
@@ -578,29 +578,6 @@ patch(MockServer.prototype, 'mail', {
     // Private Mocked Methods
     //--------------------------------------------------------------------------
 
-    /**
-     * Simulates `_sendone` on `bus.bus`.
-     *
-     * @param {string} channel
-     * @param {string} notificationType
-     * @param {any} message
-     */
-     _mockBusBus__sendone(channel, notificationType, message) {
-        this._mockBusBus__sendmany([[channel, notificationType, message]]);
-    },
-    /**
-     * Simulates `_sendmany` on `bus.bus`.
-     *
-     * @param {Array} notifications
-     */
-    _mockBusBus__sendmany(notifications) {
-        const values = [];
-        for (const notification of notifications) {
-            const [type, payload] = notification.slice(1, notification.length);
-            values.push({ payload, type });
-        }
-        owl.Component.env.services['bus_service'].trigger('notification', values);
-    },
     /**
      * Simulates `_attachment_format` on `ir.attachment`.
      *
diff --git a/addons/mail/static/tests/helpers/webclient_setup.js b/addons/mail/static/tests/helpers/webclient_setup.js
index 01a67fa4b8d..9b75490197b 100644
--- a/addons/mail/static/tests/helpers/webclient_setup.js
+++ b/addons/mail/static/tests/helpers/webclient_setup.js
@@ -18,7 +18,8 @@ import { registry } from '@web/core/registry';
 import { patchWithCleanup } from "@web/../tests/helpers/utils";
 import { createWebClient } from "@web/../tests/webclient/helpers";
 
-const WEBCLIENT_LOAD_ROUTES = [
+const ROUTES_TO_IGNORE = [
+    '/longpolling/poll',
     '/web/webclient/load_menus',
     '/web/dataset/call_kw/res.users/load_views',
     '/web/dataset/call_kw/res.users/systray_get_activities'
@@ -90,7 +91,6 @@ function setupMessagingServiceRegistries({
             const originalService = busService.start(...arguments);
             Object.assign(originalService, {
                 _beep() {}, // Do nothing
-                _poll() {}, // Do nothing
                 _registerWindowUnload() {}, // Do nothing
                 updateOption() {},
             });
@@ -156,5 +156,5 @@ function setupMessagingServiceRegistries({
 
 export {
     getWebClientReady,
-    WEBCLIENT_LOAD_ROUTES,
+    ROUTES_TO_IGNORE,
 };
diff --git a/addons/mail/static/tests/qunit_suite_tests/chatter_tests.js b/addons/mail/static/tests/qunit_suite_tests/chatter_tests.js
index 69326a553e6..5398a3b2278 100644
--- a/addons/mail/static/tests/qunit_suite_tests/chatter_tests.js
+++ b/addons/mail/static/tests/qunit_suite_tests/chatter_tests.js
@@ -1,7 +1,7 @@
 /** @odoo-module **/
 
 import { start, startServer } from '@mail/../tests/helpers/test_utils';
-import { WEBCLIENT_LOAD_ROUTES } from '@mail/../tests/helpers/webclient_setup';
+import { ROUTES_TO_IGNORE } from '@mail/../tests/helpers/webclient_setup';
 
 import testUtils from 'web.test_utils';
 import { clickEdit, patchWithCleanup, selectDropdownItem } from '@web/../tests/helpers/utils';
@@ -21,7 +21,7 @@ QUnit.test('list activity widget with no activity', async function (assert) {
         mockRPC: function (route, args) {
             if (
                 args.method !== 'get_views' &&
-                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...WEBCLIENT_LOAD_ROUTES].includes(route)
+                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...ROUTES_TO_IGNORE].includes(route)
             ) {
                 assert.step(route);
             }
@@ -70,7 +70,7 @@ QUnit.test('list activity widget with activities', async function (assert) {
         mockRPC: function (route, args) {
             if (
                 args.method !== 'get_views' &&
-                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...WEBCLIENT_LOAD_ROUTES].includes(route)
+                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...ROUTES_TO_IGNORE].includes(route)
             ) {
                 assert.step(route);
             }
@@ -115,7 +115,7 @@ QUnit.test('list activity widget with exception', async function (assert) {
         mockRPC: function (route, args) {
             if (
                 args.method !== 'get_views' &&
-                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...WEBCLIENT_LOAD_ROUTES].includes(route)
+                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...ROUTES_TO_IGNORE].includes(route)
             ) {
                 assert.step(route);
             }
@@ -172,7 +172,7 @@ QUnit.test('list activity widget: open dropdown', async function (assert) {
         mockRPC: function (route, args) {
             if (
                 args.method !== 'get_views' &&
-                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...WEBCLIENT_LOAD_ROUTES].includes(route)
+                !['/mail/init_messaging', '/mail/load_message_failures', '/longpolling/im_status', ...ROUTES_TO_IGNORE].includes(route)
             ) {
                 assert.step(args.method || route);
             }
diff --git a/addons/web/static/tests/webclient/helpers.js b/addons/web/static/tests/webclient/helpers.js
index 326322b7027..827f24db852 100644
--- a/addons/web/static/tests/webclient/helpers.js
+++ b/addons/web/static/tests/webclient/helpers.js
@@ -52,6 +52,7 @@ import Widget from "web.Widget";
 import { uiService } from "@web/core/ui/ui_service";
 import { ClientActionAdapter, ViewAdapter } from "@web/legacy/action_adapters";
 import { commandService } from "@web/core/commands/command_service";
+import { ConnectionAbortedError } from "@web/core/network/rpc_service";
 import { CustomFavoriteItem } from "@web/search/favorite_menu/custom_favorite_item";
 import { standaloneAdapter } from "web.OwlCompatibility";
 
@@ -215,7 +216,7 @@ export async function addLegacyMockEnvironment(env, legacyParams = {}) {
         const legacyMockServer = new LegacyMockServer(legacyParams.models, { widget });
         await legacyMockServer.setup();
         const originalRPC = env.services.rpc;
-        env.services.rpc = async (...args) => {
+        const rpc = async (...args) => {
             try {
                 return await originalRPC(...args);
             } catch (e) {
@@ -226,6 +227,15 @@ export async function addLegacyMockEnvironment(env, legacyParams = {}) {
                 }
             }
         };
+        env.services.rpc = function () {
+            let rejectFn;
+            const rpcProm = new Promise((resolve, reject) => {
+                rejectFn = reject;
+                rpc(...arguments).then(resolve).catch(reject);
+            });
+            rpcProm.abort = () => rejectFn(new ConnectionAbortedError("XmlHttpRequestError abort"));
+            return rpcProm;
+        };
     }
 }