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

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scala/test/M10Extensions.test.scala

@@ -0,0 +1,52 @@
+package snake
+
+import Fixtures.*
+import M09Helpers.drawn
+
+class M10ExtensionsSuite extends munit.FunSuite:
+  cases("m10-update").foreach { c =>
+    test(s"update: ${c("name").str}") {
+      val a = c("args")
+      assertEquals(Game.update(gameState(a(0)), action(a(1))), gameState(c("expected")))
+    }
+  }
+
+  cases("m10-moves-every").foreach { c =>
+    test(s"movesEvery: ${c("name").str}") {
+      assertEquals(Game.movesEvery(c("args")(0).num.toInt), c("expected").num.toInt)
+    }
+  }
+
+  cases("m10-input").foreach { c =>
+    test(s"keyToAction: ${c("name").str}") {
+      assertEquals(Input.keyToAction(c("args")(0).str), opt(c("expected"))(action))
+    }
+  }
+
+  private def time(t: Long): Event = Event.Time(t)
+  private val frameTimes = List(25L, 50L, 75L, 100L, 125L, 150L, 175L, 200L)
+
+  test("the animation clock runs every 25 ms") { assertEquals(App.FRAME_MS, 25L) }
+
+  test("speedActions turns the clock into Frame actions every 25 ms") {
+    assertEquals(App.speedActions.run(frameTimes.map(time)), List.fill(8)(Action.Frame))
+  }
+
+  test("speedActions still turns keys into actions, including pause and restart") {
+    assertEquals(
+      App.speedActions.run(List(Event.KeyDown(" "), Event.KeyDown("r"), Event.KeyDown("ArrowUp"))),
+      List(Action.TogglePause, Action.Restart, Action.Turn(Direction.Up))
+    )
+  }
+
+  test("main (seed 42) draws a moved snake after eight 25 ms frames") {
+    val traced = IO.trace(App.main, 42)
+    assertEquals(traced.ops, List(Op.RandomSeed))
+    val (first, afterFirst) = traced.result.step(time(0))
+    assertEquals(drawn(first.head), View.view(Spawn.newGame(42)))
+    val drawings = afterFirst.run(frameTimes.map(time))
+    assertEquals(drawings.length, 8)
+    val start = Spawn.newGame(42)
+    val moved = start.copy(snake = start.snake.map(p => p.copy(x = p.x + 1)), frame = 8)
+    assertEquals(drawn(drawings(7)), View.view(moved))
+  }