Make it easier to visualize test cases in-game

[SimonAlling]

When writing test cases or trying to figure out why a test case is failing, it's usually very helpful to visualize the test case in the game.

This PR takes all test cases that don't involve multiple dynamically created sub-tests, and moves their initial states into their own modules in src/TestScenarios/, thereby enabling visualization with minimal changes in src/Main.elm:

import TestScenarios.CrashIntoWallExactTiming

init : () -> ( Model, Cmd Msg )
init _ =
    let
        ( gameState, cmd ) =
            { seedAfterSpawn = Random.initialSeed 0
            , spawnedKurves = TestScenarios.CrashIntoWallExactTiming.spawnedKurves
            }
                |> prepareReplayRound
                |> newRoundGameStateAndCmd Config.default
    in
    ( { pressedButtons = Set.empty
      , appState = InGame gameState
      , config = Config.default
      , players = initialPlayers
      }
    , cmd
    )

Moving tickNumber into src/ means that it cannot use Debug.todo anymore (because npm run build would then fail), so I went with Tick.genesis because it seemed like the most reasonable option. I guess tickNumber n would also make sense in principle, but it would cause npm test to hang indefinitely should a negative number be passed to tickNumber.

For the record, one can short-circuit update to speed up the visualization:

--- b/src/Main.elm
+++ a/src/Main.elm
@@ -98,6 +98,6 @@ stepSpawnState config { kurvesLeft, ticksLeft } =


-update : Msg -> Model -> ( Model, Cmd Msg )
-update msg ({ config, pressedButtons } as model) =
+update : Cmd Msg -> Msg -> Model -> ( Model, Cmd Msg )
+update cmdSoFar msg ({ config, pressedButtons } as model) =
     case msg of
         FocusLost ->
@@ -117,8 +117,21 @@ update msg ({ config, pressedButtons } as model) =
                 ( tickResult, cmd ) =
                     Game.reactToTick config tick midRoundState
+
+                newModel =
+                    { model | appState = InGame (tickResultToGameState tickResult) }
+
+                newCmd =
+                    Cmd.batch [ cmdSoFar, cmd ]
             in
-            ( { model | appState = InGame (tickResultToGameState tickResult) }
-            , cmd
-            )
+            case tickResult of
+                RoundKeepsGoing _ newMidRoundState ->
+                    if modBy 100 (Tick.toInt tick) == 0 then
+                        ( newModel, newCmd )
+
+                    else
+                        update newCmd (GameTick (Tick.succ tick) newMidRoundState) newModel
+
+                RoundEnds _ ->
+                    ( newModel, newCmd )

         ButtonUsed Down button ->

(Without the modBy 100 check, the StressTestRealisticTurtleSurvivalRound scenario would crash with InternalError: too much recursion.)

💡 git show --color-moved=plain --color-moved-ws=allow-indentation-change

[SimonAlling]

I have only moved some test case scenarios for starters, to give an idea of the change. All of them should be given the same treatment before merging.

[lydell]

This is awesome!

It was fun watching what StressTestRealisticTurtleSurvivalRound really looks like.