feat(fsharp): m09 input/app/runtime and m10 extensions with tests

Co-Authored-By: Claude Opus 5.5 <[email protected]>

fsharp/tests/M09App.fs

@@ -0,0 +1,63 @@
+module Snake.Tests.M09App
+
+open Expecto
+open Snake
+open Snake.Model
+open Snake.IO
+open Snake.Stream
+open Snake.Tests.M09Helpers
+
+[<Tests>]
+let tests =
+    testList "M09 App" [
+        testCase "the game ticks every 150 ms" (fun () -> Expect.equal App.TICK_MS 150L "TICK_MS")
+
+        testCase "classicActions turns the clock into Tick actions and keys into Turn actions" (fun () ->
+            Expect.equal
+                (Stream.run [ Time 150L; KeyDown "ArrowUp"; KeyDown "x"; Time 300L ] App.classicActions)
+                [ Tick; Turn Up; Tick ]
+                "actions")
+
+        testCase "states starts with the new game, then yields one state per action" (fun () ->
+            let out = App.states 42u App.classicActions |> Stream.run [ Time 150L; KeyDown "ArrowUp"; Time 300L ]
+            Expect.equal (List.length out) 4 "length"
+            Expect.equal (List.head out) (Spawn.newGame 42u) "first state"
+
+            Expect.equal
+                (out |> List.map (fun s -> List.head s.Snake))
+                [ { X = 10; Y = 10 }; { X = 11; Y = 10 }; { X = 11; Y = 10 }; { X = 11; Y = 9 } ]
+                "heads"
+
+            Expect.equal (out |> List.map (fun s -> s.NextDir)) [ Right; Right; Up; Up ] "nextDir"
+            Expect.equal (out |> List.map (fun s -> s.Dir)) [ Right; Right; Right; Up ] "dir")
+
+        testCase "render draws the whole view of the state" (fun () ->
+            Expect.equal
+                (IO.trace 0u (App.render (Spawn.newGame 42u))).Ops
+                (View.view (Spawn.newGame 42u) |> List.map Draw)
+                "ops")
+
+        testCase "main asks for a random seed, then builds the stream from it" (fun () ->
+            let traced = IO.trace 42u (App.main ())
+            Expect.equal traced.Ops [ RandomSeed ] "ops"
+            let outs, _ = Stream.step (Time 0L) traced.Result
+            Expect.equal (List.length outs) 1 "one drawing"
+            Expect.equal (drawn (List.head outs)) (View.view (Spawn.newGame 42u)) "drawing")
+
+        // `main` itself switches to speedActions in m10, so the 150 ms behaviour is checked on the same program built from classicActions.
+        testCase "the program built from classicActions draws the new game first, then the ticked game after 150 ms" (fun () ->
+            let stream = (IO.trace 42u (classicMain ())).Result
+            let first, next = Stream.step (Time 0L) stream
+            let second, _ = Stream.step (Time 150L) next
+            Expect.equal (drawn (List.head first)) (View.view (Spawn.newGame 42u)) "first drawing"
+            Expect.equal (List.length second) 1 "one more drawing"
+            Expect.notEqual (drawn (List.head second)) (drawn (List.head first)) "the game moved")
+
+        // Holds before and after m10: whatever `main` ticks with, the clock must be wired in, so time passing produces more drawings.
+        testCase "main draws again once time has passed" (fun () ->
+            let stream = (IO.trace 42u (App.main ())).Result
+            let first, next = Stream.step (Time 0L) stream
+            let later, _ = Stream.step (Time 150L) next
+            Expect.equal (List.length first) 1 "one drawing"
+            Expect.isNonEmpty later "more drawings")
+    ]