Allowed moves as function (#164)

* initial implementation of allowedMoves as function

* upated an allowed moves test to use a function

* added mentions of allowedMoves as function in docs

* update Game.md

docs/api/Game.md

@@ -119,6 +119,7 @@ const game = Game({
         onTurnEnd: ...
         onPhaseBegin: ...
         onPhaseEnd: ...
+        allowedMoves: ...
         ...
       },
       {
@@ -129,6 +130,7 @@ const game = Game({
         onTurnEnd: ...
         onPhaseBegin: ...
         onPhaseEnd: ...
+        allowedMoves: ...
         ...
       },
     ]

src/core/flow.js

@@ -217,8 +217,9 @@ export function Flow({
  *   // A phase-specific movesPerTurn.
  *   movesPerTurn: integer,
  *
- *   // List of moves that are allowed in this phase.
- *   allowedMoves: ['moveA', ...],
+ *   // List of moves or a function that returns a list of moves
+ *   // that are allowed in this phase.
+ *   allowedMoves: (G, ctx) => ['moveA', ...],
  * }
  */
 export function FlowWithPhases({
@@ -295,6 +296,10 @@ export function FlowWithPhases({
     if (conf.turnOrder === undefined) {
       conf.turnOrder = turnOrder;
     }
+    if (conf.allowedMoves && typeof conf.allowedMoves != 'function') {
+      const { allowedMoves } = conf;
+      conf.allowedMoves = () => allowedMoves;
+    }
   }
 
   const endTurnIfWrap = (G, ctx) => {
@@ -542,7 +547,7 @@ export function FlowWithPhases({
   const canMakeMoveWrap = (G, ctx, opts) => {
     const conf = phaseMap[ctx.phase] || {};
     if (conf.allowedMoves) {
-      const set = new Set(conf.allowedMoves);
+      const set = new Set(conf.allowedMoves({ G, ctx }));
       if (!set.has(opts.type)) {
         return false;
       }

src/core/flow.test.js

@@ -419,7 +419,7 @@ test('canMakeMove', () => {
 
     flow: {
       phases: [
-        { name: 'A', allowedMoves: 'A' },
+        { name: 'A', allowedMoves: () => ['A'] },
         { name: 'B', allowedMoves: 'B' },
         { name: 'C' },
       ],