diff --git a/addons/web/static/src/core/assets.js b/addons/web/static/src/core/assets.js
index 705f0110227..2a2599db9de 100644
--- a/addons/web/static/src/core/assets.js
+++ b/addons/web/static/src/core/assets.js
@@ -20,7 +20,7 @@ class AssetsLoadingError extends Error {}
  * @param {string} url the url of the script
  * @returns {Promise<true>} resolved when the script has been loaded
  */
-assets.loadJS = memoize(function loadJS(url) {
+export const _loadJS = (assets.loadJS = memoize(function loadJS(url) {
     if (document.querySelector(`script[src="${url}"]`)) {
         // Already in the DOM and wasn't loaded through this function
         // Unfortunately there is no way to check whether a script has loaded
@@ -39,7 +39,7 @@ assets.loadJS = memoize(function loadJS(url) {
             reject(new AssetsLoadingError(`The loading of ${url} failed`));
         });
     });
-});
+}));
 
 /**
  * Loads the given url as a stylesheet.
@@ -47,7 +47,7 @@ assets.loadJS = memoize(function loadJS(url) {
  * @param {string} url the url of the stylesheet
  * @returns {Promise<true>} resolved when the stylesheet has been loaded
  */
-assets.loadCSS = memoize(function loadCSS(url) {
+export const _loadCSS = (assets.loadCSS = memoize(function loadCSS(url) {
     if (document.querySelector(`link[href="${url}"]`)) {
         // Already in the DOM and wasn't loaded through this function
         // Unfortunately there is no way to check whether a link has loaded
@@ -66,7 +66,7 @@ assets.loadCSS = memoize(function loadCSS(url) {
             reject(new AssetsLoadingError(`The loading of ${url} failed`));
         });
     });
-});
+}));
 
 /**
  * Container dom containing all the owl templates that have been loaded.
@@ -84,30 +84,30 @@ let defaultApp;
  *      can be changed with setLoadXmlDefaultApp method)
  * @returns {Promise<true>} resolved when the template xml has been loaded
  */
- assets.loadXML = function loadXML (xml, app=defaultApp) {
+export const _loadXML = (assets.loadXML = function loadXML(xml, app = defaultApp) {
     const doc = new DOMParser().parseFromString(xml, "text/xml");
-    if (doc.querySelector('parsererror')) {
-        throw doc.querySelector('parsererror div').textContent.split(':')[0];
+    if (doc.querySelector("parsererror")) {
+        throw doc.querySelector("parsererror div").textContent.split(":")[0];
     }
 
     for (const element of doc.querySelectorAll("templates > [t-name][owl]")) {
         element.removeAttribute("owl");
-        const name = element.getAttribute('t-name');
+        const name = element.getAttribute("t-name");
         const previous = templates.querySelector(`[t-name="${name}"]`);
         if (previous) {
-            console.debug('Override template: ' + name);
+            console.debug("Override template: " + name);
             previous.replaceWith(element);
         } else {
             templates.documentElement.appendChild(element);
         }
     }
     if (app || defaultApp) {
-        console.debug('Add templates in Owl app.');
+        console.debug("Add templates in Owl app.");
         app.addTemplates(templates, app || defaultApp);
     } else {
-        console.debug('Add templates on window Owl container.');
+        console.debug("Add templates on window Owl container.");
     }
-};
+});
 /**
  * Update the default app to load templates.
  *
@@ -123,7 +123,7 @@ export function setLoadXmlDefaultApp(app) {
  * @param {string} bundleName Name of the bundle containing the list of files
  * @returns {Promise<{cssLibs, cssContents, jsLibs, jsContents}>}
  */
-assets.getBundle = memoize(async function getBundle(bundleName) {
+export const _getBundle = (assets.getBundle = memoize(async function getBundle(bundleName) {
     const url = new URL(`/web/bundle/${bundleName}`, location.origin);
     for (const [key, value] of Object.entries(session.bundle_params || {})) {
         url.searchParams.set(key, value);
@@ -138,9 +138,9 @@ assets.getBundle = memoize(async function getBundle(bundleName) {
     };
     for (const key in json) {
         const file = json[key];
-        if (file.type === 'link') {
+        if (file.type === "link") {
             assets.cssLibs.push(file.src);
-        } else if (file.type === 'style') {
+        } else if (file.type === "style") {
             assets.cssContents.push(file.content);
         } else {
             if (file.src) {
@@ -151,7 +151,7 @@ assets.getBundle = memoize(async function getBundle(bundleName) {
         }
     }
     return assets;
-});
+}));
 
 /**
  * Loads the given js/css libraries and asset bundles. Note that no library or
@@ -181,24 +181,24 @@ assets.getBundle = memoize(async function getBundle(bundleName) {
  *
  * @returns {Promise}
  */
-assets.loadBundle = memoize(async function loadBundle(desc) {
+export const _loadBundle = (assets.loadBundle = memoize(async function loadBundle(desc) {
     // Load css in parallel
     const promiseCSS = Promise.all((desc.cssLibs || []).map(assets.loadCSS)).then(() => {
         if (desc.cssContents && desc.cssContents.length) {
             const style = document.createElement("style");
-            style.textContent = desc.cssContents.join('\n');
+            style.textContent = desc.cssContents.join("\n");
             document.head.appendChild(style);
         }
     });
     // Load JavaScript (don't wait for the css loading)
     for (const urlData of desc.jsLibs || []) {
-        if (typeof urlData === 'string') {
+        if (typeof urlData === "string") {
             // serial loading
             await assets.loadJS(urlData);
             // Wait template if the JavaScript come from bundle.
-            const bundle = urlData.match(/\/web\/assets\/.*\/([^\/]+?)(\.min)?\.js/);
+            const bundle = urlData.match(/\/web\/assets\/.*\/([^/]+?)(\.min)?\.js/);
             if (bundle) {
-                await odoo.ready(bundle[1] + '.bundle.xml');
+                await odoo.ready(bundle[1] + ".bundle.xml");
             }
         } else {
             // parallel loading
@@ -209,44 +209,44 @@ assets.loadBundle = memoize(async function loadBundle(desc) {
     if (desc.jsContents && desc.jsContents.length) {
         const script = document.createElement("script");
         script.type = "text/javascript";
-        script.textContent = desc.jsContents.join('\n');
+        script.textContent = desc.jsContents.join("\n");
         document.head.appendChild(script);
     }
     // Wait for the scc loading to be completed before loading the other bundle
     await promiseCSS;
     // Load other desc
     for (const bundleName of desc.assetLibs || []) {
-        if (typeof bundleName === 'string') {
+        if (typeof bundleName === "string") {
             // serial loading
             const desc = await assets.getBundle(bundleName);
             await assets.loadBundle(desc);
         } else {
             // parallel loading
-            await Promise.all(bundleName.map(async bundleName => {
-                const desc = await assets.getBundle(bundleName);
-                return assets.loadBundle(desc);
-            }));
+            await Promise.all(
+                bundleName.map(async (bundleName) => {
+                    const desc = await assets.getBundle(bundleName);
+                    return assets.loadBundle(desc);
+                })
+            );
         }
     }
-});
-
+}));
 
 export const loadJS = function (url) {
     return assets.loadJS(url);
-}
+};
 export const loadCSS = function (url) {
     return assets.loadCSS(url);
-}
-export const loadXML = function (xml, app=defaultApp) {
-    return assets.loadXML(xml, app=app);
-}
+};
+export const loadXML = function (xml, app = defaultApp) {
+    return assets.loadXML(xml, app);
+};
 export const getBundle = function (bundleName) {
     return assets.getBundle(bundleName);
-}
+};
 export const loadBundle = function (desc) {
     return assets.loadBundle(desc);
-}
-
+};
 
 const { Component, xml, onWillStart } = owl;
 /**
diff --git a/addons/web/static/src/core/errors/error_utils.js b/addons/web/static/src/core/errors/error_utils.js
index d63d722562a..8ba710c9821 100644
--- a/addons/web/static/src/core/errors/error_utils.js
+++ b/addons/web/static/src/core/errors/error_utils.js
@@ -1,6 +1,6 @@
 /** @odoo-module **/
 
-import { loadJS } from "../assets";
+import { _loadJS } from "../assets"; // use the real, non patched (in tests), loadJS
 import { isBrowserChrome } from "../browser/feature_detection";
 
 /** @typedef {import("./error_service").UncaughtError} UncaughtError */
@@ -147,7 +147,7 @@ export function formatTraceback(error) {
 export async function annotateTraceback(error) {
     const traceback = formatTraceback(error);
     try {
-        await loadJS("/web/static/lib/stacktracejs/stacktrace.js");
+        await _loadJS("/web/static/lib/stacktracejs/stacktrace.js");
     } catch (_e) {
         return traceback;
     }