From 15bf8db9f468f9e3eb30865d4e40c81102ae1ecf Mon Sep 17 00:00:00 2001
From: Sven van Heugten <sven@memcmp.org>
Date: Sun, 4 Jan 2026 20:17:35 +0100
Subject: [PATCH] Make FakeHome independent of NightLightStateMachine

---
 NightLight.Core.Tests/FakeHome.fs        | 30 ++++++++----------------
 NightLight.Core.Tests/NightLightTests.fs | 26 +++++++++++++++-----
 2 files changed, 30 insertions(+), 26 deletions(-)

diff --git a/NightLight.Core.Tests/FakeHome.fs b/NightLight.Core.Tests/FakeHome.fs
index bf7aa6c..6413cbd 100644
--- a/NightLight.Core.Tests/FakeHome.fs
+++ b/NightLight.Core.Tests/FakeHome.fs
@@ -3,7 +3,6 @@ namespace NightLight.Core.Tests
 open System
 open System.Text.RegularExpressions
 open NightLight.Core.Models
-open NightLight.Core.Core
 open FsToolkit.ErrorHandling
 open FSharp.Data
 
@@ -44,19 +43,19 @@ type FakeLight(light: Light) =
             color <- newColor
 
 type FakeHome() =
-    let mutable nightLightStateMachine = NightLightStateMachine()
-
-    let assertIsOkAndGet result =
-        match result with
-        | Ok value -> value
-        | Error error -> failwith $"Expected Ok, got Error {error}"
-
     let friendlyNameToFakeLight =
         lights
         |> Seq.map (fun light -> light.FriendlyName, FakeLight light)
         |> Map.ofSeq
 
-    let processCommand command =
+    let onEventPublished = new Event<Event>()
+
+    member _.LightStates = friendlyNameToFakeLight.Values |> Seq.map _.LightWithState
+
+    [<CLIEvent>]
+    member _.OnEventPublished = onEventPublished.Publish
+
+    member _.ProcessCommand(command: Message) =
         option {
             let! friendlyName =
                 let m = Regex.Match(command.Topic, "^zigbee2mqtt/(.+)/set$")
@@ -86,15 +85,6 @@ type FakeHome() =
         }
         |> ignore
 
-    let sendEvent event =
-        let newState, commands =
-            event |> nightLightStateMachine.OnEventReceived |> assertIsOkAndGet
-
-        commands |> Seq.iter processCommand
-        nightLightStateMachine <- newState
-
-    member _.LightStates = friendlyNameToFakeLight.Values |> Seq.map _.LightWithState
-
     member _.Interact(interaction: Interaction) =
         match interaction with
         | HumanInteraction(LightTurnedOn light) ->
@@ -107,9 +97,9 @@ type FakeHome() =
                     ""data"": {{ ""friendly_name"": ""{light.FriendlyName}"" }}
                   }}" }
             |> ReceivedZigbeeEvent
-            |> sendEvent
+            |> onEventPublished.Trigger
         | HumanInteraction(LightTurnedOff light) -> friendlyNameToFakeLight[light.FriendlyName].TurnOff()
-        | TimeChanged newTime -> newTime |> Event.TimeChanged |> sendEvent
+        | TimeChanged newTime -> newTime |> Event.TimeChanged |> onEventPublished.Trigger
 
 type FakeHome with
     member this.Interact(interactions: Interaction seq) = interactions |> Seq.iter this.Interact
diff --git a/NightLight.Core.Tests/NightLightTests.fs b/NightLight.Core.Tests/NightLightTests.fs
index 612ad49..cc8edfc 100644
--- a/NightLight.Core.Tests/NightLightTests.fs
+++ b/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)