solver support for 3x4/4x3 boards

src/shared/gameplay/solver.ts

@@ -60,7 +60,9 @@ export const getPreferredNextOutcome = (
 };
 
 export const computeAllSolutions = (rows: number, columns: number, rules: GameRules) => {
-  if (rows * columns > 9) {
+  if (rows * columns > 12) {
+    // Even for 3x5 board computing all solutions takes 20 seconds on my computer.
+    // There are probably many opportunities for optimization, but they're outside of the scope for now.
     throw new Error("Board is too large, solving requires too many computational resources");
   }
 

src/shared/integration-tests/tictactoe-all.test.ts

@@ -0,0 +1,17 @@
+import t from "tap";
+
+import { tictactoeThreeRules } from "../game-variants/tictactoe/tictactoe-three-rules.ts";
+import { checkSolutionsIncomplete } from "./test-helpers.ts";
+
+const rules = tictactoeThreeRules;
+
+void t.test("computeAllSolutions", async (t) => {
+  // These numbers are not checked, but at least these tests will help us catch possible changes
+  void t.test("number of combinations for 3x4 board", async (t) => {
+    checkSolutionsIncomplete(t, rules, 3, 4, 111973, {});
+  });
+
+  void t.test("number of combinations for 4x3 board", async (t) => {
+    checkSolutionsIncomplete(t, rules, 4, 3, 111973, {});
+  });
+});

src/shared/integration-tests/tictactoe-three.test.ts

@@ -4,12 +4,12 @@ import { FinalOutcome, Player } from "../datatypes/types.ts";
 import { createOpponent } from "../gameplay/opponent.ts";
 import { computeAllSolutions } from "../gameplay/solver.ts";
 import { tictactoeThreeRules } from "../game-variants/tictactoe/tictactoe-three-rules.ts";
-import { checkNextMove, checkSolutionsComplete } from "./test-helpers.ts";
+import { checkNextMove, checkSolutionsComplete, checkSolutionsIncomplete } from "./test-helpers.ts";
 
 const rules = tictactoeThreeRules;
 
 void t.test("computeAllSolutions", async (t) => {
-  // smallest possible board where X can win
+  void t.test("1x5, smallest possible board where X can win", async (t) => {
     checkSolutionsComplete(t, rules, 1, 5, {
       _____: { finalOutcome: FinalOutcome.Draw, movesLeft: 5 },
 
@@ -114,6 +114,15 @@ void t.test("computeAllSolutions", async (t) => {
     });
   });
 
+  void t.test("number of combinations for 3x4 board", async (t) => {
+    checkSolutionsIncomplete(t, rules, 3, 4, 111973, {});
+  });
+
+  void t.test("number of combinations for 4x3 board", async (t) => {
+    checkSolutionsIncomplete(t, rules, 4, 3, 111973, {});
+  });
+});
+
 void t.test("createOpponent", async (t) => {
   void t.test("1x5 board", async (t) => {
     const outcomes = computeAllSolutions(1, 5, rules);