Fix: Handle non-configurable properties in instrumenter for expect.toThrow

code/addons/test/template/stories/basics.stories.ts

@@ -101,7 +101,7 @@ export const WithLoaders = {
   },
 };
 
-const UserEventSetup = {
+export const UserEventSetup = {
   play: async (context) => {
     const { args, canvasElement, step, userEvent } = context;
     const canvas = within(canvasElement);
@@ -132,4 +132,28 @@ const UserEventSetup = {
   },
 };
 
-export { UserEventSetup };
+/**
+ * Demonstrates the expect.toThrow functionality from issue #28406
+ * https://github.com/storybookjs/storybook/issues/28406
+ *
+ * This tests various forms of throw assertions to ensure they all work correctly.
+ */
+export const ToThrow = {
+  play: async () => {
+    await expect(() => {
+      throw new Error('test error');
+    }).toThrow();
+
+    await expect(() => {
+      throw new Error('specific error');
+    }).toThrowError();
+
+    await expect(() => {
+      throw new Error('specific message');
+    }).toThrow('specific message');
+
+    await expect(() => {
+      // This doesn't throw
+    }).not.toThrow();
+  },
+};

code/core/src/instrumenter/instrumenter.ts

@@ -355,12 +355,14 @@ export class Instrumenter {
       (acc, key) => {
         const descriptor = getPropertyDescriptor(obj, key);
         if (typeof descriptor?.get === 'function') {
-          const getter = () => descriptor?.get?.bind(obj)?.();
-          Object.defineProperty(acc, key, {
-            get: () => {
-              return this.instrument(getter(), { ...options, path: path.concat(key) }, depth);
-            },
-          });
+          if (descriptor.configurable) {
+            const getter = () => descriptor?.get?.bind(obj)?.();
+            Object.defineProperty(acc, key, {
+              get: () => {
+                return this.instrument(getter(), { ...options, path: path.concat(key) }, depth);
+              },
+            });
+          }
           return acc;
         }