Fix for exception-unhandled "forked" Promise chain (#2101)

See #2100

Co-authored-by: Tim Schilling <schilling711@gmail.com>

Author: karolyi

debug_toolbar/static/debug_toolbar/js/toolbar.js

@@ -321,16 +321,25 @@ const djdt = {
 
         const origFetch = window.fetch;
         window.fetch = function (...args) {
+            // Heads up! Before modifying this code, please be aware of the
+            // possible unhandled errors that might arise from changing this.
+            // For details, see
+            // https://github.com/django-commons/django-debug-toolbar/pull/2100
             const promise = origFetch.apply(this, args);
-            promise.then((response) => {
+            return promise.then((response) => {
                 if (response.headers.get("djdt-store-id") !== null) {
-                    handleAjaxResponse(response.headers.get("djdt-store-id"));
+                    try {
+                        handleAjaxResponse(
+                            response.headers.get("djdt-store-id")
+                        );
+                    } catch (err) {
+                        throw new Error(
+                            `"${err.name}" occurred within django-debug-toolbar: ${err.message}`
+                        );
+                    }
                 }
-                // Don't resolve the response via .json(). Instead
-                // continue to return it to allow the caller to consume as needed.
                 return response;
             });
-            return promise;
         };
     },
     cookie: {

docs/changes.rst

@@ -15,6 +15,7 @@ Pending
 * Added a Makefile target (``make help``) to get a quick overview
   of each target.
 * Avoided reinitializing the staticfiles storage during instrumentation.
+* Fix for exception-unhandled "forked" Promise chain in rebound window.fetch
 
 5.0.1 (2025-01-13)
 ------------------