fix(solidstart): Read server action route from the request's root span

packages/solidstart/src/server/withServerActionInstrumentation.ts

@@ -1,6 +1,6 @@
 import { handleCallbackErrors, SPAN_STATUS_ERROR } from '@sentry/core';
 import { flushIfServerless } from '@sentry/core/server';
-import { captureException, getActiveSpan, spanToJSON, startSpan } from '@sentry/node';
+import { captureException, getActiveSpan, getRootSpan, spanToJSON, startSpan } from '@sentry/node';
 import { isRedirect } from './utils';
 import {
   SENTRY_SEGMENT_NAME_SOURCE,
@@ -25,7 +25,9 @@ export async function withServerActionInstrumentation<A extends (...args: unknow
   const activeSpan = getActiveSpan();
 
   if (activeSpan) {
-    const spanData = spanToJSON(activeSpan).attributes;
+    // Read the request's `http.server` root span, which is the span we rename. The active span is
+    // usually a framework handler span (e.g. Nitro's h3 `handler` span) without any URL attributes.
+    const spanData = spanToJSON(getRootSpan(activeSpan)).attributes;
 
     // In solid start, server function calls are made to `/_server` which doesn't tell us
     // a lot. We rewrite the span's route to be that of the sever action name but only

packages/solidstart/test/server/withServerActionInstrumentation.test.ts

@@ -169,6 +169,28 @@ describe('withServerActionInstrumentation', () => {
     expect(mockSpanSetAttribute).to.toHaveBeenCalledWith(SENTRY_SEGMENT_NAME_SOURCE, 'route');
   });
 
+  it('sets a server action name on the root span when the active span is a nested handler span', async () => {
+    const rootSpan = new SentryCore.SentrySpan({
+      attributes: {
+        'url.path': '/_server',
+        [SENTRY_OP]: 'http.server',
+      },
+    });
+    const handlerSpan = new SentryCore.SentrySpan({
+      attributes: {
+        [SENTRY_OP]: 'handler',
+      },
+    });
+    SentryCore.addChildSpanToSpan(rootSpan, handlerSpan);
+    mockGetActiveSpan.mockReturnValue(handlerSpan);
+    const mockRootSpanSetAttribute = vi.spyOn(rootSpan, 'setAttribute');
+
+    await serverActionGetPrefecture();
+
+    expect(mockRootSpanSetAttribute).toHaveBeenCalledWith('http.route', 'getPrefecture');
+    expect(mockRootSpanSetAttribute).toHaveBeenCalledWith(SENTRY_SEGMENT_NAME_SOURCE, 'route');
+  });
+
   it('does not set a server action name if the active span had a non `/_server` `url.path`', async () => {
     const span = new SentryCore.SentrySpan();
     span.setAttribute('url.path', '/users/5');