fix(app): fix excessive /runs network requests (#14783)

Closes EXEC-255

UseNotifyService utilizes hostname instead of the host object, preventing a pass by reference issue causing excessive requests sent to /runs that often occurs on the RobotDetails page. Let's also ensure that if a robot loses connection while a component has passed a callback to appShellListener, we ensure we remove the correct callback from the store.

app/src/resources/__tests__/useNotifyService.test.ts

@@ -165,4 +165,20 @@ describe('useNotifyService', () => {
     unmount()
     expect(mockAppShellListener).toHaveBeenCalled()
   })
+
+  it('should still clean up the listener if the hostname changes to null after subscribing', () => {
+    const { unmount, rerender } = renderHook(() =>
+      useNotifyService({
+        hostOverride: MOCK_HOST_CONFIG,
+        topic: MOCK_TOPIC,
+        setRefetchUsingHTTP: mockHTTPRefetch,
+        options: MOCK_OPTIONS,
+      })
+    )
+    rerender({ hostOverride: null })
+    unmount()
+    expect(appShellListener).toHaveBeenCalledWith(
+      expect.objectContaining({ hostname: MOCK_HOST_CONFIG.hostname })
+    )
+  })
 })

app/src/resources/useNotifyService.ts

@@ -43,6 +43,7 @@ export function useNotifyService<TData, TError = Error>({
   const doTrackEvent = useTrackEvent()
   const isFlex = useIsFlex(host?.robotName ?? '')
   const hasUsedNotifyService = React.useRef(false)
+  const seenHostname = React.useRef<string | null>(null)
   const { enabled, staleTime, forceHttpPolling } = options
 
   const shouldUseNotifications =
@@ -62,21 +63,22 @@ export function useNotifyService<TData, TError = Error>({
       })
       dispatch(notifySubscribeAction(hostname, topic))
       hasUsedNotifyService.current = true
+      seenHostname.current = hostname
     } else {
       setRefetchUsingHTTP('always')
     }
 
     return () => {
       if (hasUsedNotifyService.current) {
         appShellListener({
-          hostname: hostname as string,
+          hostname: seenHostname.current as string,
           topic,
           callback: onDataEvent,
           isDismounting: true,
         })
       }
     }
-  }, [topic, host, shouldUseNotifications])
+  }, [topic, hostname, shouldUseNotifications])
 
   function onDataEvent(data: NotifyResponseData): void {
     if (data === 'ECONNFAILED' || data === 'ECONNREFUSED') {