Better unit tests

src/Fabulous.Tests/APISketchTests/APISketchTests.fs

@@ -954,7 +954,7 @@ module ViewHelpers =
         childButton.Tap()
 
     [<Test>]
-    let ``Cascading View.map produces the right result`` () =
+    let ``Several layers of View.map produce the right result`` () =
         let mutable expectedMsg = Unchecked.defaultof<GrandParentMsg>
 
         let childView =
@@ -976,7 +976,7 @@ module ViewHelpers =
 
                 (View.map ParentMessage parentView)
                     .automationId("parentStack")
-                    .tap2(GrandParentTap)
+                    .tapContainer(GrandParentTap)
             }
 
 
@@ -1014,3 +1014,41 @@ module ViewHelpers =
 
         expectedMsg <- GrandParentTap
         parentStack.Tap()
+
+    [<Test>]
+    let ``Cascading View.map produce the right result`` () =
+        let mutable expectedMsg = Unchecked.defaultof<GrandParentMsg>
+
+        let childView =
+            Button("Child button", ChildClick)
+                .automationId("childButton")
+
+        let parentView =
+            (View.map ChildMessage childView).tap(ParentTap)
+
+        let grandParentView model =
+            (View.map ParentMessage parentView)
+                .tap2(GrandParentTap)
+
+        let init () = true
+
+        let update msg model =
+            Assert.AreEqual(expectedMsg, msg)
+            not model
+
+        let program =
+            StatefulWidget.mkSimpleView init update grandParentView
+
+        let instance = Run.Instance program
+        let tree = instance.Start()
+
+        let childButton = find<TestButton> tree "childButton"
+
+        expectedMsg <- ParentMessage(ChildMessage ChildClick)
+        childButton.Press()
+
+        expectedMsg <- ParentMessage ParentTap
+        childButton.Tap()
+
+        expectedMsg <- GrandParentTap
+        childButton.Tap2()

src/Fabulous.Tests/APISketchTests/TestUI.Attributes.fs

@@ -61,6 +61,32 @@ module TestUI_Attributes =
 
             { Key = key; Name = name }
 
+        let defineTappable2 name : ScalarAttributeDefinition<obj, obj> =
+            let key =
+                ScalarAttributeDefinition.CreateAttributeData<obj, obj>(
+                    (fun x -> x),
+                    ScalarAttributeComparers.noCompare,
+                    (fun _ newValueOpt node ->
+
+                        let btn = node.Target :?> IButton
+
+                        match node.TryGetHandler<int>(name) with
+                        | ValueNone -> ()
+                        | ValueSome handlerId -> btn.RemoveTap2Listener handlerId
+
+                        match newValueOpt with
+                        | ValueNone -> node.SetHandler(name, ValueNone)
+
+                        | ValueSome msg ->
+                            let handler () = Dispatcher.dispatch node msg
+
+                            let handlerId = btn.AddTap2Listener handler
+                            node.SetHandler<int>(name, ValueSome handlerId))
+                )
+                |> AttributeDefinitionStore.registerScalar
+
+            { Key = key; Name = name }
+
         let defineContainerTappable name : ScalarAttributeDefinition<obj, obj> =
             let key =
                 ScalarAttributeDefinition.CreateAttributeData<obj, obj>(
@@ -116,6 +142,7 @@ module TestUI_Attributes =
         module Button =
             let Pressed = definePressable "Button_Pressed"
             let Tap = defineTappable "Button_Tap"
+            let Tap2 = defineTappable2 "Button_Tap2"
 
 
         module Automation =

src/Fabulous.Tests/APISketchTests/TestUI.Platform.fs

@@ -27,6 +27,8 @@ module Platform =
         abstract RemovePressListener: int -> unit
         abstract AddTapListener: ButtonHandler -> int
         abstract RemoveTapListener: int -> unit
+        abstract AddTap2Listener: ButtonHandler -> int
+        abstract RemoveTap2Listener: int -> unit
 
     type LabelChangeList =
         | TextSet of string
@@ -82,8 +84,10 @@ module Platform =
         inherit TestViewElement()
         let mutable pressCounter: int = 1
         let mutable tapCounter: int = 1
+        let mutable tap2Counter: int = 1
         let pressHandlers = Dictionary<int, ButtonHandler>()
         let tapHandlers = Dictionary<int, ButtonHandler>()
+        let tap2Handlers = Dictionary<int, ButtonHandler>()
 
         member _.Press() =
             for handler in Array.ofSeq(pressHandlers.Values) do
@@ -93,6 +97,10 @@ module Platform =
             for handler in Array.ofSeq(tapHandlers.Values) do
                 handler()
 
+        member _.Tap2() =
+            for handler in Array.ofSeq(tap2Handlers.Values) do
+                handler()
+
         interface IText with
             member val Text = "" with get, set
             member val TextColor = "" with get, set
@@ -112,6 +120,13 @@ module Platform =
 
             member this.RemoveTapListener(id) = tapHandlers.Remove(id) |> ignore
 
+            member this.AddTap2Listener(handler) =
+                tap2Handlers.Add(tap2Counter, handler)
+                tap2Counter <- tap2Counter + 1
+                tap2Counter - 1
+
+            member this.RemoveTap2Listener(id) = tap2Handlers.Remove(id) |> ignore
+
 
     type TestNumericBag() =
         inherit TestViewElement()

src/Fabulous.Tests/APISketchTests/TestUI.Widgets.fs

@@ -118,7 +118,16 @@ module TestUI_Widgets =
 
 
         [<Extension>]
-        static member inline tap2<'msg, 'marker when 'marker :> TestStackMarker>
+        static member inline tap2<'msg, 'marker when 'marker :> TestButtonMarker>
+            (
+                this: WidgetBuilder<'msg, 'marker>,
+                value: 'msg
+            ) =
+            this.AddScalar(Attributes.Button.Tap2.WithValue(value))
+
+
+        [<Extension>]
+        static member inline tapContainer<'msg, 'marker when 'marker :> TestStackMarker>
             (
                 this: WidgetBuilder<'msg, 'marker>,
                 value: 'msg