Re-write the remaining tests

NightLight.Core.Tests/FakeHome.fs

@@ -147,5 +147,12 @@ type FakeHome with
     member this.LightsThatAreOn =
         this.LightStates |> Seq.filter (snd >> _.IsOn) |> Seq.toList
 
-    member this.LightShouldHaveState light condition =
-        this.LightStates |> Seq.find (fst >> (=) light) |> snd |> condition
+    member this.NonRemotelyControlledLightStates =
+        this.LightStates
+        |> Seq.filter (fst >> _.ControlledWithRemote >> (=) NonRemote)
+        |> Seq.toList
+
+    member this.RemotelyControlledLightStates =
+        this.LightStates
+        |> Seq.filter (fst >> _.ControlledWithRemote >> (<>) NonRemote)
+        |> Seq.toList

NightLight.Core.Tests/InteractionListGenerators.fs

@@ -1,14 +1,15 @@
 module NightLight.Core.Tests.InteractionListGenerators
 
-open FsCheck.FSharp
+open System
 open NightLight.Core.Models
-open NightLight.Core.Tests.TimeChangedGenerators
 open FsCheck
+open FsCheck.FSharp
 
-let private genHumanInteraction maybeBiasTowardsLight =
-    match maybeBiasTowardsLight with
-    | Some biasTowardsLight -> Gen.oneof [ Gen.constant biasTowardsLight; Gen.elements lights ]
-    | None -> Gen.elements lights
+let private genTimeChanged =
+    ArbMap.defaults |> ArbMap.generate<DateTime> |> Gen.map Interaction.TimeChanged
+
+let private genHumanInteraction =
+    Gen.elements lights
     |> Gen.bind (fun light -> Gen.elements [ LightPoweredOn light; LightPoweredOff light ])
     |> Gen.map Interaction.HumanInteraction
 
@@ -16,86 +17,18 @@ let private genRemoteInteraction =
     Gen.elements [ RemotePressedOnButton; RemotePressedOffButton; RemotePressedLeftButton ]
     |> Gen.map RemoteInteraction
 
-let private genInteraction maybeBiasTowardsLight =
-    Gen.oneof
-        [ genTimeChanged
-          genHumanInteraction maybeBiasTowardsLight
-          genRemoteInteraction ]
+let private genInteraction =
+    Gen.oneof [ genTimeChanged; genHumanInteraction; genRemoteInteraction ]
 
-let genBiasedInteractionsExcept biasTowardsLight disqualifier =
-    Some biasTowardsLight
-    |> genInteraction
-    |> Gen.filter (not << disqualifier)
-    |> Gen.listOf
+let private genInteractions = genInteraction |> Gen.listOf
 
-let genBiasedInteractions biasTowardsLight =
-    genBiasedInteractionsExcept biasTowardsLight (fun _ -> false)
-
-let genInteractions = genInteraction None |> Gen.listOf
-
-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 ensureStartsWithTimeChanged (genInteractions: Gen<Interaction list>) =
+let private ensureStartsWithTimeChanged (genInteractions: Gen<Interaction list>) =
     genInteractions
     |> Gen.bind (fun interactions ->
         match interactions with
         | Interaction.TimeChanged _ :: _ -> Gen.constant interactions
         | _ -> genTimeChanged |> Gen.map (fun tc -> tc :: interactions))
 
-let ensureLightHasPower (light: Light) (genInteractions: Gen<Interaction list>) =
-    genInteractions
-    |> Gen.map (fun interactions ->
-        if doesLightHavePowerAfterInteractions light interactions then
-            interactions
-        else
-            interactions @ [ HumanInteraction(LightPoweredOn light) ])
-
-let ensurePartOfDayIs (desiredPartOfDay: PartOfDay) (genInteractions: Gen<Interaction list>) =
-    genInteractions
-    |> Gen.bind (fun interactions ->
-        if getPartOfDayAfterInteractions interactions = desiredPartOfDay then
-            Gen.constant interactions
-        else
-            desiredPartOfDay
-            |> genTimeChangedToPartOfDay
-            |> Gen.map (fun tc -> interactions @ [ tc ]))
-
-let ensureLastRemoteInteractionIs
-    (desiredLastRemoteInteraction: RemoteInteraction)
-    (genInteractions: Gen<Interaction list>)
-    =
-    genInteractions
-    |> Gen.map (fun interactions ->
-        let maybeLastRemoteInteraction =
-            interactions
-            |> Seq.choose (fun interaction ->
-                match interaction with
-                | Interaction.RemoteInteraction remoteInteraction -> Some remoteInteraction
-                | _ -> None)
-            |> Seq.tryLast
-
-        if maybeLastRemoteInteraction = Some desiredLastRemoteInteraction then
-            interactions
-        else
-            interactions @ [ RemoteInteraction desiredLastRemoteInteraction ])
-
 type ArbitraryInteractions() =
     static member Interactions() =
         genInteractions |> ensureStartsWithTimeChanged |> Arb.fromGen

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

NightLight.Core.Tests/NightLight.Core.Tests.fsproj

@@ -9,8 +9,8 @@
     <ItemGroup>
         <Compile Include="FakeHome.fs" />
         <Compile Include="GenHelpers.fs" />
-        <Compile Include="TimeChangedGenerators.fs" />
         <Compile Include="InteractionListGenerators.fs" />
+        <Compile Include="InteractionListHelpers.fs" />
         <Compile Include="LightArbitraries.fs" />
         <Compile Include="NightLightTests.fs" />
     </ItemGroup>

NightLight.Core.Tests/NightLightTests.fs

@@ -1,9 +1,8 @@
 namespace NightLight.Core.Tests
 
 open NightLight.Core.Core
-open NightLight.Core.Tests.GenHelpers
-open NightLight.Core.Tests.TimeChangedGenerators
 open NightLight.Core.Tests.InteractionListGenerators
+open NightLight.Core.Tests.InteractionListHelpers
 open NightLight.Core.Models
 open FsCheck.Xunit
 open FsCheck.FSharp
@@ -42,105 +41,50 @@ type NightLightTests() =
         |> Prop.trivial (fakeHome.LightsThatAreOn.Length = 0)
 
     [<Property(Arbitrary = [| typeof<ArbitraryInteractions> |])>]
-    let ``All non-remotely controlled lights that have power should be on`` (interactions: Interaction list) =
+    let ``All non-remotely controlled lights with power should be on`` (interactions: Interaction list) =
         let fakeHome = createFakeHomeWithNightLightAndInteract interactions
 
         let nonRemotelyControlledLightsWithPower =
-            fakeHome.LightStates
-            |> Seq.filter (fun (light, _) ->
-                light.ControlledWithRemote = NonRemote
-                && doesLightHavePowerAfterInteractions light interactions)
+            fakeHome.NonRemotelyControlledLightStates
+            |> Seq.filter (fun (light, _) -> doesLightHavePowerAfterInteractions light interactions)
             |> Seq.toList
 
         nonRemotelyControlledLightsWithPower
         |> Seq.forall (snd >> _.IsOn)
-        |> Prop.trivial (nonRemotelyControlledLightsWithPower.Length = 0)
         |> Prop.collect $"{nonRemotelyControlledLightsWithPower.Length} non-remotely controlled light(s) with power"
+        |> Prop.trivial (nonRemotelyControlledLightsWithPower.Length = 0)
 
-    [<Property(Arbitrary = [| typeof<ArbitraryRemotelyControlledLight> |])>]
-    let ``If the remote was never used, all remote controlled lights with power should be on`` (light: Light) =
-        genBiasedInteractionsExcept light _.IsRemoteInteraction
-        |> ensureLightHasPower light
-        |> ensureStartsWithTimeChanged
-        |> Arb.fromGen
-        |> Prop.forAll
-        <| fun interactions ->
+    [<Property(Arbitrary = [| typeof<ArbitraryInteractions> |])>]
+    let ``All remotely-controlled lights with power should have the correct state`` (interactions: Interaction list) =
         let fakeHome = createFakeHomeWithNightLightAndInteract interactions
-            fakeHome.LightShouldHaveState light _.IsOn
 
-    [<Property(Arbitrary = [| typeof<ArbitraryRemotelyControlledLight> |])>]
-    let ``If the last button that was pressed on the remote is 'On', all remotely controlled lights with power should be on``
-        (light: Light)
-        =
-        genBiasedInteractions light
-        |> ensureLastRemoteInteractionIs RemotePressedOnButton
-        |> ensureLightHasPower light
-        |> ensureStartsWithTimeChanged
-        |> Arb.fromGen
-        |> Prop.forAll
-        <| fun interactions ->
-            let fakeHome = createFakeHomeWithNightLightAndInteract interactions
-            fakeHome.LightShouldHaveState light _.IsOn
+        let remotelyControlledLightsWithPower =
+            fakeHome.RemotelyControlledLightStates
+            |> Seq.filter (fun (light, _) -> doesLightHavePowerAfterInteractions light interactions)
+            |> Seq.toList
 
-    [<Property(Arbitrary = [| typeof<ArbitraryRemotelyControlledLight> |])>]
-    let ``If a new day has started and the remote hasn't been used yet, all remotely controlled lights with power should be on``
-        (light: Light)
-        =
-        concatGens
-            [ genBiasedInteractions light
-              |> ensureStartsWithTimeChanged
-              |> ensurePartOfDayIs Night
-              genTimeChangedToPartOfDay Day |> Gen.map List.singleton
-              genBiasedInteractionsExcept light _.IsRemoteInteraction ]
-        |> ensureLightHasPower light
-        |> Arb.fromGen
-        |> Prop.forAll
-        <| fun interactions ->
-            let fakeHome = createFakeHomeWithNightLightAndInteract interactions
-            fakeHome.LightShouldHaveState light _.IsOn
+        let allOn (ls: (Light * LightState) seq) = ls |> Seq.forall (snd >> _.IsOn)
+        let allOff (ls: (Light * LightState) seq) = ls |> Seq.forall (snd >> _.IsOff)
 
-    [<Property(Arbitrary = [| typeof<ArbitraryRemotelyControlledLight> |])>]
-    let ``If the last button that was pressed on the remote is 'Off' and a new day hasn't started yet, all remotely controlled lights should be off``
-        (light: Light)
-        =
-        concatGens
-            [ genBiasedInteractions light
-              RemoteInteraction RemotePressedOffButton |> List.singleton |> Gen.constant
-              genBiasedInteractionsExcept light (fun interaction ->
-                  interaction.IsRemoteInteraction || interaction |> isTimeChangedToPartOfDay Day) ]
-        |> ensureStartsWithTimeChanged
-        |> Arb.fromGen
-        |> Prop.forAll
-        <| fun interactions ->
-            let fakeHome = createFakeHomeWithNightLightAndInteract interactions
-            fakeHome.LightShouldHaveState light _.IsOff
+        let controlledBy remote ls =
+            ls |> Seq.filter (fst >> _.ControlledWithRemote >> (=) remote)
 
-    [<Property(Arbitrary = [| typeof<ArbitraryLeftRemotelyControlledLight> |])>]
-    let ``If the last button that was pressed on the remote is 'Left', all left-side remotely controlled lights with power should be on``
-        (light: Light)
-        =
-        genBiasedInteractions light
-        |> ensureLastRemoteInteractionIs RemotePressedLeftButton
-        |> ensureStartsWithTimeChanged
-        |> ensureLightHasPower light
-        |> Arb.fromGen
-        |> Prop.forAll
-        <| fun interactions ->
-            let fakeHome = createFakeHomeWithNightLightAndInteract interactions
-            fakeHome.LightShouldHaveState light _.IsOn
+        let maybeLastRemoteInteraction = tryGetLastRemoteInteraction interactions
 
-    [<Property(Arbitrary = [| typeof<ArbitraryRightRemotelyControlledLight> |])>]
-    let ``If the last button that was pressed on the remote is 'Left' and a new day hasn't started yet, all right-side remotely controlled lights should be off``
-        (light: Light)
-        =
-        concatGens
-            [ genBiasedInteractions light
-              RemoteInteraction RemotePressedLeftButton |> List.singleton |> Gen.constant
-              genBiasedInteractionsExcept light (fun interaction ->
-                  interaction.IsRemoteInteraction || interaction |> isTimeChangedToPartOfDay Day) ]
-        |> ensureStartsWithTimeChanged
-        |> Arb.fromGen
-        |> Prop.forAll
-        <| fun interactions ->
-            let fakeHome = createFakeHomeWithNightLightAndInteract interactions
-            fakeHome.LightShouldHaveState light _.IsOff
+        let hasNewDayStartedSinceThen =
+            hasNewDayStartedSince interactions maybeLastRemoteInteraction
+
+        if hasNewDayStartedSinceThen then
+            remotelyControlledLightsWithPower |> allOn
+        else
+            match maybeLastRemoteInteraction with
+            | Some(_, RemotePressedOnButton) -> remotelyControlledLightsWithPower |> allOn
+            | Some(_, RemotePressedOffButton) -> remotelyControlledLightsWithPower |> allOff
+            | Some(_, RemotePressedLeftButton) ->
+                remotelyControlledLightsWithPower |> controlledBy RemoteLeft |> allOn
+                && remotelyControlledLightsWithPower |> controlledBy RemoteRight |> allOff
+            | None -> remotelyControlledLightsWithPower |> allOn
+        |> Prop.collect $"last remote interaction is {maybeLastRemoteInteraction}"
+        |> Prop.collect $"{remotelyControlledLightsWithPower.Length} remotely controlled light(s) with power"
+        |> Prop.classify hasNewDayStartedSinceThen "new day has started since then"
+        |> Prop.trivial (remotelyControlledLightsWithPower.Length = 0)

NightLight.Core.Tests/TimeChangedGenerators.fs

@@ -1,28 +0,0 @@
-module NightLight.Core.Tests.TimeChangedGenerators
-
-open System
-open FsCheck.FSharp
-
-type PartOfDay =
-    | Day
-    | Night
-
-let getPartOfDay (dateTime: DateTime) =
-    match dateTime with
-    | _ when
-        dateTime.TimeOfDay >= TimeSpan.FromHours 6
-        && dateTime.TimeOfDay < TimeSpan.FromHours 20.5
-        ->
-        Day
-    | _ -> Night
-
-let genTimeChanged =
-    ArbMap.defaults |> ArbMap.generate<DateTime> |> Gen.map Interaction.TimeChanged
-
-let isTimeChangedToPartOfDay partOfDay interaction =
-    match interaction with
-    | TimeChanged time when getPartOfDay time = partOfDay -> true
-    | _ -> false
-
-let genTimeChangedToPartOfDay (partOfDay: PartOfDay) =
-    genTimeChanged |> Gen.filter (isTimeChangedToPartOfDay partOfDay)