Added [NotNullWhen(true)] (#856)

Author: phillipsawyer

src/HassModel/NetDeamon.HassModel/Entities/EntityExtensions.cs

@@ -10,28 +10,28 @@ public static class EntityExtensions
     /// </summary>
     /// <param name="entityState">The state to check</param>
     /// <returns>true if the state equals "on", otherwise false</returns>
-    public static bool IsOn(this EntityState? entityState) => string.Equals(entityState?.State, "on", StringComparison.OrdinalIgnoreCase);
+    public static bool IsOn([NotNullWhen(true)] this EntityState? entityState) => string.Equals(entityState?.State, "on", StringComparison.OrdinalIgnoreCase);
 
     /// <summary>
     /// Checks if an EntityState has the state "off" 
     /// </summary>
     /// <param name="entityState">The state to check</param>
     /// <returns>true if the state equals "off", otherwise false</returns>
-    public static bool IsOff(this EntityState? entityState) => string.Equals(entityState?.State, "off", StringComparison.OrdinalIgnoreCase);
+    public static bool IsOff([NotNullWhen(true)] this EntityState? entityState) => string.Equals(entityState?.State, "off", StringComparison.OrdinalIgnoreCase);
 
     /// <summary>
     /// Checks if an Entity has the state "on" 
     /// </summary>
     /// <param name="entity">The state to check</param>
     /// <returns>true if the state equals "on", otherwise false</returns>
-    public static bool IsOn(this Entity? entity) => entity?.EntityState?.IsOn() ?? false;
+    public static bool IsOn([NotNullWhen(true)] this Entity? entity) => entity?.EntityState?.IsOn() ?? false;
 
     /// <summary>
     /// Checks if an Entity has the state "off" 
     /// </summary>
     /// <param name="entity">The state to check</param>
     /// <returns>true if the state equals "off", otherwise false</returns>
-    public static bool IsOff(this Entity? entity) => entity?.EntityState?.IsOff() ?? false;
+    public static bool IsOff([NotNullWhen(true)] this Entity? entity) => entity?.EntityState?.IsOff() ?? false;
 
     /// <summary>Gets a NumericEntity from a given Entity</summary>
     public static NumericEntity AsNumeric(this Entity entity) => new(entity);
@@ -56,4 +56,4 @@ public static NumericEntity<TAttributes> WithAttributesAs<TAttributes>(this Nume
 
     internal static IObservable<T> StateChangesOnly<T>(this IObservable<T> changes) where T : StateChange
         => changes.Where(c => c.New?.State != c.Old?.State);
-}
+}