v0.4.4 — New Game dialog for the opening hand and the three revenue rates, Yard renamed Interchange, and two movement bugs behind a mirrored consist

src/web/game.ts

@@ -42,8 +42,15 @@ import {
   trainName,
   variantLabel,
 } from '../sim/view.ts';
-import { HAND_LIMIT, mainlineProfile, trainProfile } from '../engine/content.ts';
-import type { Hand, TrackGeometry } from '../engine/content.ts';
+import {
+  DEFAULT_HOUSE_RULES,
+  HAND_LIMIT,
+  LEGACY_HOUSE_RULES,
+  houseRules,
+  mainlineProfile,
+  trainProfile,
+} from '../engine/content.ts';
+import type { Hand, HouseRuleOverrides, TrackGeometry } from '../engine/content.ts';
 import type { Port } from '../engine/track.ts';
 import { connectionsFor, joins, neighbour, variantsFor } from '../engine/track.ts';
 import { areaOf, trainNeedingCars } from '../engine/apply.ts';
@@ -59,8 +66,16 @@ export const SOLO_CONFIG: GameConfig = {
     employeeRotation: false,
     emergencyToolbox: false,
   },
+  // Spelt out rather than left to fall through, so a save written by the page always names the rules
+  // it was played under — see `Save.rules`.
+  houseRules: DEFAULT_HOUSE_RULES,
 };
 
+/** The same config with the New Game dialog's answers in it. */
+export function configWith(rules: HouseRuleOverrides): GameConfig {
+  return { ...SOLO_CONFIG, houseRules: houseRules({ houseRules: rules }) };
+}
+
 /** A group of legal actions of one kind, ready to put on screen. */
 export type ActionGroup = {
   kind: string;
@@ -708,10 +723,31 @@ function record(game: Game, events: GameEvent[], actor: PlayerIndex | null = nul
 // Saving — seed plus intents, replayed
 // ---------------------------------------------------------------------------
 
-export type Save = { seed: number; history: Intent[] };
+/**
+ * A save is a seed, the house rules it was dealt under, and the intents submitted.
+ *
+ * `rules` is optional because saves written before the New Game dialog existed do not have it, and
+ * those replay under `LEGACY_HOUSE_RULES` — see `configFor`. Everything written from now on carries
+ * its rules, so a save can never again be silently re-dealt by a change of default.
+ */
+export type Save = { seed: number; history: Intent[]; rules?: HouseRuleOverrides };
 
 export function toSave(game: Game): Save {
-  return { seed: game.seed, history: game.history };
+  const rules = game.state.config.houseRules;
+  return rules ? { seed: game.seed, history: game.history, rules } : { seed: game.seed, history: game.history };
+}
+
+/**
+ * THE CONFIG A SAVE MUST BE REPLAYED UNDER, which is not necessarily today's default.
+ *
+ * A save is a seed and a list of intents: replay it under different rules and it is a different
+ * game, and the symptom is not an error but a replay that quietly stops early. `TODO.md` records
+ * that happening twice unnoticed, once 42 intents into 360. So a save that names its rules gets
+ * exactly those, and a save that names none is from before the dialog and gets the rules that were
+ * in force then — never the current defaults.
+ */
+function configFor(save: Save, config: GameConfig): GameConfig {
+  return { ...config, houseRules: save.rules ?? LEGACY_HOUSE_RULES };
 }
 
 /**
@@ -736,7 +772,9 @@ export function toSave(game: Game): Save {
  */
 export function undo(game: Game, config: GameConfig = SOLO_CONFIG): Game | null {
   if (game.history.length === 0) return null;
-  return fromSave({ seed: game.seed, history: game.history.slice(0, -1) }, config);
+  // `toSave` first, so the rules this game was dealt under come with it. Rebuilding the save by hand
+  // here dropped them, and undo re-dealt the game under the defaults instead of its own settings.
+  return fromSave({ ...toSave(game), history: game.history.slice(0, -1) }, config);
 }
 
 /**
@@ -747,7 +785,7 @@ export function undo(game: Game, config: GameConfig = SOLO_CONFIG): Game | null
  * stops the replay rather than being forced — better a short game than a corrupt one.
  */
 export function fromSave(save: Save, config: GameConfig = SOLO_CONFIG): Game {
-  const game = newGame(save.seed, config);
+  const game = newGame(save.seed, configFor(save, config));
   for (const intent of save.history) {
     const actor = currentActor(game);
     if (actor === null) break;