feat(scala): m01–m06 port with shared fixtures

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

scala/test/M05Game.test.scala

@@ -0,0 +1,39 @@
+package snake
+
+import Fixtures.*
+
+class M05GameSuite extends munit.FunSuite:
+  cases("m05-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("m05-replay").foreach { c =>
+    test(s"replay: ${c("name").str}") {
+      val a = c("args")
+      assertEquals(Game.replay(gameState(a(0)), list(a(1))(action)), gameState(c("expected")))
+    }
+  }
+
+  cases("m05-history").foreach { c =>
+    test(s"history: ${c("name").str}") {
+      val a = c("args")
+      assertEquals(Game.history(gameState(a(0)), list(a(1))(action)), list(c("expected"))(gameState))
+    }
+  }
+
+  private val replayArgs = cases("m05-replay")(0)("args")
+  private val start = gameState(replayArgs(0))
+  private val actions = list(replayArgs(1))(action)
+
+  test("history has one more state than there are actions") {
+    assertEquals(Game.history(start, actions).length, actions.length + 1)
+  }
+
+  test("history starts at the start state and ends where replay ends") {
+    val states = Game.history(start, actions)
+    assertEquals(states.head, start)
+    assertEquals(states.last, Game.replay(start, actions))
+  }