feat(convex): add throw error button to convex example (#3256)

Add a "Throw Error" button to test PostHog error tracking's first-party
Convex integration without depending on posthog.captureException.

Author: richardsolomou

examples/example-convex/convex/example.ts

@@ -115,6 +115,15 @@ export const testCaptureException = mutation({
   },
 })
 
+export const testThrowError = mutation({
+  args: {
+    errorMessage: v.string(),
+  },
+  handler: async (_ctx, args) => {
+    throw new Error(args.errorMessage)
+  },
+})
+
 // --- Feature flag methods (actions) ---
 
 const featureFlagArgs = {

examples/example-convex/src/App.tsx

@@ -122,6 +122,7 @@ function App() {
   const groupIdentifyM = useMutation(api.example.testGroupIdentify)
   const aliasM = useMutation(api.example.testAlias)
   const captureExceptionM = useMutation(api.example.testCaptureException)
+  const throwErrorM = useMutation(api.example.testThrowError)
 
   const agentManualA = useAction(api.convexAgent.manualCapture.generate)
   const agentTracedA = useAction(api.convexAgent.withTracing.generate)
@@ -431,6 +432,18 @@ function App() {
             >
               Capture Exception
             </button>
+            <button
+              {...btnProps('throwError')}
+              onClick={() =>
+                run('throwError', () =>
+                  throwErrorM({
+                    errorMessage: errorMsg,
+                  })
+                )
+              }
+            >
+              Throw Error
+            </button>
           </div>
         </Section>