Re-write the remaining tests

NightLight.Core.Tests/InteractionListHelpers.fs

@@ -0,0 +1,61 @@
+module NightLight.Core.Tests.InteractionListHelpers
+
+open System
+
+type PartOfDay =
+    | Day
+    | Night
+
+let private getPartOfDay (dateTime: DateTime) =
+    match dateTime with
+    | _ when
+        dateTime.TimeOfDay >= TimeSpan.FromHours 6
+        && dateTime.TimeOfDay < TimeSpan.FromHours 20.5
+        ->
+        Day
+    | _ -> Night
+
+let getPartOfDayAfterInteractions interactions =
+    interactions
+    |> Seq.choose (fun interaction ->
+        match interaction with
+        | Interaction.TimeChanged time -> Some time
+        | _ -> None)
+    |> Seq.last
+    |> getPartOfDay
+
+let doesLightHavePowerAfterInteractions light interactions =
+    interactions
+    |> Seq.choose (fun interaction ->
+        match interaction with
+        | HumanInteraction(LightPoweredOff l) when l = light -> Some false
+        | HumanInteraction(LightPoweredOn l) when l = light -> Some true
+        | _ -> None)
+    |> Seq.tryLast
+    |> Option.defaultValue false
+
+let tryGetLastRemoteInteraction interactions =
+    interactions
+    |> Seq.indexed
+    |> Seq.choose (fun interaction ->
+        match interaction with
+        | index, Interaction.RemoteInteraction remoteInteraction -> Some(index, remoteInteraction)
+        | _ -> None)
+    |> Seq.tryLast
+
+let hasNewDayStartedSince interactions maybeSince =
+    let maybeLastNightToDayTransitionIndex =
+        interactions
+        |> Seq.indexed
+        |> Seq.choose (fun (index, interaction) ->
+            match interaction with
+            | Interaction.TimeChanged time -> Some(index, getPartOfDay time)
+            | _ -> None)
+        |> Seq.pairwise
+        |> Seq.tryFindBack (fun ((_, v1), (_, v2)) -> v1 = Night && v2 = Day)
+        |> Option.map (fun ((_, _), (i2, _)) -> i2)
+
+    match maybeLastNightToDayTransitionIndex, maybeSince with
+    | Some lastNightToDayTransitionIndex, Some(sinceIndex, _) -> sinceIndex < lastNightToDayTransitionIndex
+    | Some _, None -> true
+    | None, _ -> false