Make FakeHome independent of NightLightStateMachine

NightLight.Core.Tests/NightLightTests.fs

@@ -1,6 +1,7 @@
 namespace NightLight.Core.Tests
 
 open System
+open NightLight.Core.Core
 open FsCheck.Xunit
 open FsCheck.FSharp
 
@@ -26,24 +27,37 @@ module InteractionsHelpers =
 
 [<Properties(Arbitrary = [| typeof<Arbitraries> |])>]
 type NightLightTests() =
+    let createFakeHomeWithNightLightAndInteract (interactions: Interaction list) =
+        let mutable nightLightStateMachine = NightLightStateMachine()
+
+        let fakeHome = FakeHome()
+
+        fakeHome.OnEventPublished.Add(fun event ->
+            match event |> nightLightStateMachine.OnEventReceived with
+            | Ok(newState, commands) ->
+                commands |> Seq.iter fakeHome.ProcessCommand
+                nightLightStateMachine <- newState
+            | Error error -> failwith $"Unexpected error {error}")
+
+        fakeHome.Interact interactions
+
+        fakeHome
+
     [<Property>]
     let ``Brightness should always be under 255`` (interactions: Interaction list) =
-        let fakeHome = FakeHome()
-        fakeHome.Interact interactions
+        let fakeHome = createFakeHomeWithNightLightAndInteract interactions
         fakeHome.ForAllLightsThatAreOn(fun (_, brightness, _) -> brightness < 255uy)
 
     [<Property>]
     let ``Lights should be red during the night`` (interactions: Interaction list) =
-        let fakeHome = FakeHome()
-        fakeHome.Interact interactions
+        let fakeHome = createFakeHomeWithNightLightAndInteract interactions
 
         InteractionsHelpers.isNightAfter interactions
         ==> fakeHome.ForAllLightsThatAreOn(fun (_, _, color) -> color = Red)
 
     [<Property>]
     let ``Lights should be white or yellow during the day`` (interactions: Interaction list) =
-        let fakeHome = FakeHome()
-        fakeHome.Interact interactions
+        let fakeHome = createFakeHomeWithNightLightAndInteract interactions
 
         InteractionsHelpers.isDayAfter interactions
         ==> fakeHome.ForAllLightsThatAreOn(fun (_, _, color) -> color = White || color = Yellow)