feat(nextjs): Improve client stack traces

packages/nextjs/src/client/index.ts

@@ -69,6 +69,22 @@ function addClientIntegrations(options: BrowserOptions): void {
         // Filename wasn't a properly formed URL, so there's nothing we can do
       }
 
+      if (frame.filename && frame.filename.startsWith('app:///_next')) {
+        // We need to URI-decode the filename because Next.js has wildcard routes like "/users/[id].js" which show up as "/users/%5id%5.js" in Error stacktraces.
+        // The corresponding sources that Next.js generates have proper brackets so we also need proper brackets in the frame so that source map resolving works.
+        frame.filename = decodeURI(frame.filename);
+      }
+
+      if (
+        frame.filename &&
+        frame.filename.match(
+          /^app:\/\/\/_next\/static\/chunks\/(main-|main-app-|polyfills-|webpack-|framework-|framework\.)[0-9a-f]+\.js$/,
+        )
+      ) {
+        // We don't care about these frames. It's Next.js internal code.
+        frame.in_app = false;
+      }
+
       return frame;
     },
   });

packages/nextjs/test/integration/pages/[id]/errorClick.tsx

@@ -0,0 +1,11 @@
+const ButtonPage = (): JSX.Element => (
+  <button
+    onClick={() => {
+      throw new Error('Sentry Frontend Error');
+    }}
+  >
+    Throw Error
+  </button>
+);
+
+export default ButtonPage;

packages/nextjs/test/integration/test/client/errorClick.test.ts

@@ -5,7 +5,7 @@ import { Event } from '@sentry/types';
 test('should capture error triggered on click', async ({ page }) => {
   await page.goto('/errorClick');
 
-  const [_, events] = await Promise.all([
+  const [, events] = await Promise.all([
     page.click('button'),
     getMultipleSentryEnvelopeRequests<Event>(page, 1, { envelopeType: 'event' }),
   ]);
@@ -15,3 +15,45 @@ test('should capture error triggered on click', async ({ page }) => {
     value: 'Sentry Frontend Error',
   });
 });
+
+test('should have a non-url-encoded top frame in route with parameter', async ({ page }) => {
+  await page.goto('/some-param/errorClick');
+
+  const [, events] = await Promise.all([
+    page.click('button'),
+    getMultipleSentryEnvelopeRequests<Event>(page, 1, { envelopeType: 'event' }),
+  ]);
+
+  const frames = events[0]?.exception?.values?.[0].stacktrace?.frames;
+
+  expect(frames?.[frames.length - 1].filename).toMatch(/\/\[id\]\/errorClick-[a-f0-9]+\.js$/);
+});
+
+test('should mark nextjs internal frames as `in_app`: false', async ({ page }) => {
+  await page.goto('/some-param/errorClick');
+
+  const [, events] = await Promise.all([
+    page.click('button'),
+    getMultipleSentryEnvelopeRequests<Event>(page, 1, { envelopeType: 'event' }),
+  ]);
+
+  const frames = events[0]?.exception?.values?.[0].stacktrace?.frames;
+
+  expect(frames).toContainEqual(
+    expect.objectContaining({
+      filename: expect.stringMatching(
+        /^app:\/\/\/_next\/static\/chunks\/(main-|main-app-|polyfills-|webpack-|framework-|framework\.)[0-9a-f]+\.js$/,
+      ),
+      in_app: false,
+    }),
+  );
+
+  expect(frames).not.toContainEqual(
+    expect.objectContaining({
+      filename: expect.stringMatching(
+        /^app:\/\/\/_next\/static\/chunks\/(main-|main-app-|polyfills-|webpack-|framework-|framework\.)[0-9a-f]+\.js$/,
+      ),
+      in_app: true,
+    }),
+  );
+});