From 87830303ae2777a4e5ae756da1f65be948e3a686 Mon Sep 17 00:00:00 2001
From: Robert Dailey <rcdailey@gmail.com>
Date: Sat, 11 Jun 2022 13:18:12 -0500
Subject: [PATCH] chore: Add NotNull extension method for IObservable

The main purpose of this is to force type `T` to not be nullable. If you
just use `Where()`, then you still get `IObservable<T?>`.
---
 src/Common/Extensions/RxExtensions.cs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/Common/Extensions/RxExtensions.cs b/src/Common/Extensions/RxExtensions.cs
index bdc1575d..b1088732 100644
--- a/src/Common/Extensions/RxExtensions.cs
+++ b/src/Common/Extensions/RxExtensions.cs
@@ -43,4 +43,11 @@ public static class RxExtensions
             }
         });
     }
+
+    // Borrowed from: https://stackoverflow.com/a/59434717/157971
+    public static IObservable<T> NotNull<T>(this IObservable<T?> observable)
+        where T : class
+    {
+        return observable.Where(x => x is not null).Select(x => x!);
+    }
 }