fix(core): Fix undo/redo if the move changed the stage (#701)

* Fix for null last move if changed the stage

* Added reducer test with using stages

* ESlint fixes and test logic fixes

* Fixed playerID in reducer undo/redo test

* feat(core): Mark numPlayers as optional in InitializeGame

* test(core): Convert reducer tests to TS & break up undo/redo tests

* test(core): Fix makeMove call in undo/redo test

* test(core): Improve test labelling

* feat(core): Move undo/redo stack update after event processing

* test(core): Remove unnecessary seed in test setup

* fix(core): Lookup undoable move from restore state not last state

* fix(core): Use playerID instead of currentPlayer in undoable move lookup

* test(core): Add low-level tests for undo/redo stacks

* feat(core): Don’t add move to update stack if turn was ended

Co-authored-by: delucis <swithinbank@gmail.com>

src/core/flow.ts

@@ -699,16 +699,6 @@ export function Flow({
     const G = conf.turn.wrapped.onMove(state);
     state = { ...state, G };
 
-    // Update undo / redo state.
-    const undo = state._undo || [];
-    const moveType = action.type;
-
-    state = {
-      ...state,
-      _undo: [...undo, { G: state.G, ctx: state.ctx, moveType }],
-      _redo: [],
-    };
-
     let events = [{ fn: OnMove }];
 
     return Process(state, events);

src/core/initialize.ts

@@ -20,7 +20,7 @@ export function InitializeGame({
   setupData,
 }: {
   game: Game;
-  numPlayers: number;
+  numPlayers?: number;
   setupData?: any;
 }) {
   game = ProcessGameConfig(game);