move towards auto-import

Stars Assistant/Helpers/RxExtensions.cs

@@ -35,4 +35,23 @@ public static class RxExtensions
         return src.Buffer(zeroCrossings);
     }
 
+    /// <summary>
+    /// Throttle a FileSystemObserver and eliminate all duplicates.
+    /// </summary>
+    /// <remarks>
+    /// Curtesy of https://endjin.com/blog/2024/05/observe-file-system-changes-with-rx-dotnet
+    /// </remarks>
+    /// <param name="watcher">An observer created with <c>ObserveFileSystem</c></param>
+    /// <param name="inactivitySeconds">Throttling window, defaults to 1 second.</param>
+    /// <param name="scheduler">Scheduler to user for throttling, default is set by <c>Quiescent</c></param>
+    /// <returns>A throttled observer with duplicate elimination.</returns>
+    public static IObservable<IEnumerable<FileSystemEventArgs>> ThrottleAndDistinct (
+        this IObservable<FileSystemEventArgs> watcher, 
+        int inactivitySeconds = 1,
+        IScheduler? scheduler = null)
+    {
+        return watcher
+                .Quiescent(TimeSpan.FromSeconds(inactivitySeconds), scheduler)
+                .Select(changes => changes.DistinctBy(x => (x.ChangeType, x.FullPath)));
+    }
 }