From 02f2f1be74d671777588bf7903a224c6a8daf648 Mon Sep 17 00:00:00 2001
From: Michael Ficocelli <ficocemt@gmail.com>
Date: Fri, 22 Aug 2025 16:12:09 -0400
Subject: [PATCH] IPVGO: Ensure getValidMoves correctly handles playing as
 white (#2292)

---
 src/Go/boardState/boardState.ts             | 5 +++++
 src/Go/effects/netscriptGoImplementation.ts | 8 +++++++-
 src/NetscriptFunctions/Go.ts                | 2 +-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/Go/boardState/boardState.ts b/src/Go/boardState/boardState.ts
index 56269d7eb..92bc3071b 100644
--- a/src/Go/boardState/boardState.ts
+++ b/src/Go/boardState/boardState.ts
@@ -71,11 +71,16 @@ export function getNewBoardStateFromSimpleBoard(
   simpleBoard: SimpleBoard,
   priorSimpleBoard?: SimpleBoard,
   ai: GoOpponent = GoOpponent.Netburners,
+  priorColor: GoColor | undefined = undefined,
 ): BoardState {
   const newState = getNewBoardState(simpleBoard.length, ai, false, updatedBoardFromSimpleBoard(simpleBoard));
   if (priorSimpleBoard) {
     newState.previousBoards.push(priorSimpleBoard.join(""));
+  }
 
+  if (priorColor) {
+    newState.previousPlayer = priorColor;
+  } else if (priorSimpleBoard) {
     // Identify the previous player based on the difference in pieces
     const priorWhitePieces = priorSimpleBoard.join("").match(/O/g)?.length ?? 0;
     const priorBlackPieces = priorSimpleBoard.join("").match(/X/g)?.length ?? 0;
diff --git a/src/Go/effects/netscriptGoImplementation.ts b/src/Go/effects/netscriptGoImplementation.ts
index 73ea0d4fc..5b753e89f 100644
--- a/src/Go/effects/netscriptGoImplementation.ts
+++ b/src/Go/effects/netscriptGoImplementation.ts
@@ -426,6 +426,7 @@ export function validateBoardState(
   error: (s: string) => never,
   _boardState?: unknown,
   _priorBoardState?: unknown,
+  playAsWhite = false,
 ): BoardState | undefined {
   const simpleBoard = getSimpleBoardFromUnknown(error, _boardState);
   const priorSimpleBoard = getSimpleBoardFromUnknown(error, _priorBoardState);
@@ -435,7 +436,12 @@ export function validateBoardState(
   }
 
   try {
-    return getNewBoardStateFromSimpleBoard(simpleBoard, priorSimpleBoard);
+    return getNewBoardStateFromSimpleBoard(
+      simpleBoard,
+      priorSimpleBoard,
+      undefined,
+      playAsWhite ? GoColor.black : GoColor.white,
+    );
   } catch (e) {
     error(boardValidity.failedToCreateBoard);
   }
diff --git a/src/NetscriptFunctions/Go.ts b/src/NetscriptFunctions/Go.ts
index 496344667..35b30bd52 100644
--- a/src/NetscriptFunctions/Go.ts
+++ b/src/NetscriptFunctions/Go.ts
@@ -97,7 +97,7 @@ export function NetscriptGo(): InternalAPI<NSGo> {
           return getValidMoves(undefined, true);
         }
         const playAsWhite = helpers.boolean(ctx, "playAsWhite", _playAsWhite ?? false);
-        const State = validateBoardState(error(ctx), _boardState, _priorBoardState);
+        const State = validateBoardState(error(ctx), _boardState, _priorBoardState, playAsWhite);
         return getValidMoves(State, playAsWhite);
       },
       getChains: (ctx) => (_boardState) => {