isamu · Oct 18, 2026 · Oct 18, 2026 · Oct 18, 2026
diff --git a/.github/workflows/pull_request.yaml b/.github/workflows/pull_request.yaml
@@ -51,6 +51,9 @@ jobs:
     - run: yarn install --frozen-lockfile --network-timeout 120000
     - run: yarn run typecheck
     - run: yarn run lint
+    # Windows checkouts get CRLF line endings, which prettier reports as unformatted.
+    - run: yarn run format:check
+      if: runner.os == 'Linux'
     - run: yarn run build
     # Sanity-check `npm pack` only once (Linux + Node 24) to avoid
     # 6-way artifact-name collisions; lint/build coverage is what

diff --git a/.prettierignore b/.prettierignore
@@ -0,0 +1,4 @@
+.scoria/
+scoria.config.json
+dist/
+coverage/
diff --git a/.prettierrc b/.prettierrc
@@ -0,0 +1,3 @@
+{
+  "printWidth": 160
+}
diff --git a/demo/App.vue b/demo/App.vue
@@ -19,11 +19,7 @@
     <div v-if="ViewComponent" class="bg-gray-800 rounded-lg p-5 mb-5 shadow-md">
       <h2 class="text-gray-200 text-xl mb-4">View Component</h2>
       <div class="border border-gray-600 rounded h-[600px]">
-        <component
-          :is="ViewComponent"
-          :selectedResult="result"
-          :sendTextMessage="handleSendMessage"
-        />
+        <component :is="ViewComponent" :selectedResult="result" :sendTextMessage="handleSendMessage" />
       </div>
     </div>
 
@@ -44,16 +40,11 @@
 <script setup lang="ts">
 import { ref, computed } from "vue";
 import { plugin, executeGo } from "../src/vue";
-import type {
-  ToolResult,
-  ToolSample,
-  ToolPlugin,
-  SendTextMessageOptions,
-} from "gui-chat-protocol/vue";
+import type { ToolResult, ToolSample, ToolPlugin, SendTextMessageOptions } from "gui-chat-protocol/vue";
 import type { GoArgs, GoState, GoClickData } from "../src/core/types";
 import { playGo } from "../src/core/logic";
 
 const currentPlugin = plugin as unknown as ToolPlugin;

 const pluginName = computed(() => currentPlugin.toolDefinition.name);
 const samplesList = computed(() => currentPlugin.samples || []);
@@ -70,8 +61,8 @@
 });

 const executeSample = async (sample: ToolSample) => {
  const args = sample.args as unknown as GoArgs;
  const execResult = await executeGo({} as any, args);
  result.value = {
    ...result.value,
    ...execResult,
@@ -85,7 +76,7 @@

  // If data is provided (from handleCellClick), process the move
  if (options?.data) {
    const clickData = options.data as GoClickData;
    processUserMove(clickData);
  }
 };
@@ -115,11 +106,7 @@
   };
 
   // If it's now computer's turn and game is not over, make computer move
-  if (
-    !newState.isTerminal &&
-    !newState.error &&
-    newState.playerNames[newState.currentSide] === "computer"
-  ) {
+  if (!newState.isTerminal && !newState.error && newState.playerNames[newState.currentSide] === "computer") {
     // Small delay for visual feedback
     setTimeout(() => {
       makeComputerMove(newState);

diff --git a/package.json b/package.json
@@ -32,7 +32,9 @@
     "build": "vite build && vue-tsc -p tsconfig.build.json --emitDeclarationOnly",
     "typecheck": "vue-tsc --noEmit",
     "lint": "eslint src demo",
-    "quality": "scoria"
+    "quality": "scoria",
+    "format": "prettier --write \"{src,demo}/**/*.{ts,tsx,vue,json,css}\" \"*.{ts,js,json}\"",
+    "format:check": "prettier --check \"{src,demo}/**/*.{ts,tsx,vue,json,css}\" \"*.{ts,js,json}\""
   },
   "peerDependencies": {
     "gui-chat-protocol": "^2.1.0",
@@ -48,6 +50,7 @@
     "eslint-plugin-vue": "^10.11.1",
     "globals": "^17.13.0",
     "gui-chat-protocol": "^2.3.0",
+    "prettier": "^3.9.10",
     "scoria": "^0.4.1",
     "tailwindcss": "^4.3.3",
     "typescript": "~6.0.3",

diff --git a/src/core/definition.ts b/src/core/definition.ts
@@ -17,27 +17,23 @@ export const TOOL_DEFINITION: ToolDefinition = {
       action: {
         type: "string",
         enum: ["new_game", "move", "pass"],
-        description:
-          "The action to perform: start a new game, make a move, or pass the turn",
+        description: "The action to perform: start a new game, make a move, or pass the turn",
       },
       col: {
         type: "number",
-        description:
-          "Column position for the move (0-8, required for 'move' action). The user will tell you the column by specifying A to J (skipping I)",
+        description: "Column position for the move (0-8, required for 'move' action). The user will tell you the column by specifying A to J (skipping I)",
         minimum: 0,
         maximum: 8,
       },
       row: {
         type: "number",
-        description:
-          "Row position for the move (0-8, required for 'move' action). The user will tell you the row by specifying 1 to 9",
+        description: "Row position for the move (0-8, required for 'move' action). The user will tell you the row by specifying 1 to 9",
         minimum: 0,
         maximum: 8,
       },
       board: {
         type: "array",
-        description:
-          "Current 9x9 board state (required for 'move' and 'pass' actions)",
+        description: "Current 9x9 board state (required for 'move' and 'pass' actions)",
         items: {
           type: "array",
           items: {
@@ -49,13 +45,11 @@ export const TOOL_DEFINITION: ToolDefinition = {
       currentSide: {
         type: "string",
         enum: ["B", "W"],
-        description:
-          "Current player's side (required for 'move' and 'pass' actions)",
+        description: "Current player's side (required for 'move' and 'pass' actions)",
       },
       playerNames: {
         type: "object",
-        description:
-          "Player assignments (required for 'move' and 'pass' actions)",
+        description: "Player assignments (required for 'move' and 'pass' actions)",
         properties: {
           B: {
             type: "string",
@@ -70,8 +64,7 @@ export const TOOL_DEFINITION: ToolDefinition = {
       },
       capturedStones: {
         type: "object",
-        description:
-          "Count of captured stones for each player (required for 'move' and 'pass' actions)",
+        description: "Count of captured stones for each player (required for 'move' and 'pass' actions)",
         properties: {
           B: {
             type: "number",
@@ -86,16 +79,14 @@ export const TOOL_DEFINITION: ToolDefinition = {
       },
       consecutivePasses: {
         type: "number",
-        description:
-          "Number of consecutive passes (required for 'pass' action, 0-2)",
+        description: "Number of consecutive passes (required for 'pass' action, 0-2)",
         minimum: 0,
         maximum: 2,
       },
       firstPlayer: {
         type: "string",
         enum: ["user", "computer"],
-        description:
-          "Optional: Which player should play as Black (goes first) for 'new_game' action. If not specified, will be chosen randomly.",
+        description: "Optional: Which player should play as Black (goes first) for 'new_game' action. If not specified, will be chosen randomly.",
       },
     },
     required: ["action"],

diff --git a/src/core/index.ts b/src/core/index.ts
@@ -2,26 +2,8 @@
  * Go Plugin - Core Entry Point
  */
 
-export type {
-  Cell,
-  Side,
-  GoBoard,
-  GoCellValue,
-  GoPlayerType,
-  GoArgs,
-  GoState,
-  Command,
-  NewGameCommand,
-  MoveCommand,
-} from "./types";
+export type { Cell, Side, GoBoard, GoCellValue, GoPlayerType, GoArgs, GoState, Command, NewGameCommand, MoveCommand } from "./types";
 
-export {
-  TOOL_NAME,
-  TOOL_DEFINITION,
-  SYSTEM_PROMPT,
-  executeGo,
-  pluginCore,
-  playGo,
-} from "./plugin";
+export { TOOL_NAME, TOOL_DEFINITION, SYSTEM_PROMPT, executeGo, pluginCore, playGo } from "./plugin";
 
 export { samples } from "./samples";
diff --git a/src/core/logic.ts b/src/core/logic.ts
@@ -16,7 +16,7 @@
 function createEmptyBoard(): GoBoard {
  const board: GoBoard = [];
  for (let i = 0; i < BOARD_SIZE; i++) {
    board[i] = new Array(BOARD_SIZE).fill(".") as Cell[];
  }
  return board;
 }
@@ -34,12 +34,7 @@
 }
 
 // Find all stones connected to the stone at (row, col)
-function getGroup(
-  board: GoBoard,
-  row: number,
-  col: number,
-  visited: boolean[][],
-): { row: number; col: number }[] {
+function getGroup(board: GoBoard, row: number, col: number, visited: boolean[][]): { row: number; col: number }[] {
   const color = board[row][col];
   if (color === ".") return [];
 
@@ -47,7 +42,7 @@
  const stack: { row: number; col: number }[] = [{ row, col }];

  while (stack.length > 0) {
    const pos = stack.pop()!;
    const r = pos.row;
    const c = pos.col;

@@ -67,10 +62,7 @@
 }
 
 // Check if a group has any liberties (empty adjacent spaces)
-function hasLiberties(
-  board: GoBoard,
-  group: { row: number; col: number }[],
-): boolean {
+function hasLiberties(board: GoBoard, group: { row: number; col: number }[]): boolean {
   for (const { row, col } of group) {
     for (const [dr, dc] of DIRECTIONS) {
       const r = row + dr;
@@ -84,10 +76,7 @@
 }
 
 // Remove captured stones and return count
-function removeCapturedStones(
-  board: GoBoard,
-  opponentSide: Side,
-): { board: GoBoard; capturedCount: number } {
+function removeCapturedStones(board: GoBoard, opponentSide: Side): { board: GoBoard; capturedCount: number } {
   const newBoard = copyBoard(board);
   const visited: boolean[][] = Array(BOARD_SIZE)
     .fill(null)
@@ -113,12 +102,7 @@
 }
 
 // Check if a move is legal (not suicide rule)
-function isLegalMove(
-  board: GoBoard,
-  row: number,
-  col: number,
-  side: Side,
-): boolean {
+function isLegalMove(board: GoBoard, row: number, col: number, side: Side): boolean {
   // Position must be empty
   if (board[row][col] !== ".") {
     return false;
@@ -130,10 +114,7 @@
 
   // First, check if this move captures opponent stones
   const opponentSide = getOpponent(side);
-  const { board: boardAfterCapture } = removeCapturedStones(
-    testBoard,
-    opponentSide,
-  );
+  const { board: boardAfterCapture } = removeCapturedStones(testBoard, opponentSide);
 
   // Then check if our own group has liberties (suicide rule)
   const visited: boolean[][] = Array(BOARD_SIZE)
@@ -144,21 +125,13 @@
   return hasLiberties(boardAfterCapture, ourGroup);
 }
 
-function makeMove(
-  board: GoBoard,
-  row: number,
-  col: number,
-  side: Side,
-): { newBoard: GoBoard; capturedCount: number } {
+function makeMove(board: GoBoard, row: number, col: number, side: Side): { newBoard: GoBoard; capturedCount: number } {
   const newBoard = copyBoard(board);
   newBoard[row][col] = side;
 
   // Remove captured opponent stones
   const opponentSide = getOpponent(side);
-  const { board: finalBoard, capturedCount } = removeCapturedStones(
-    newBoard,
-    opponentSide,
-  );
+  const { board: finalBoard, capturedCount } = removeCapturedStones(newBoard, opponentSide);
 
   return { newBoard: finalBoard, capturedCount };
 }
@@ -201,7 +174,7 @@
        const adjacentColors = new Set<Cell>();

        while (stack.length > 0) {
          const pos = stack.pop()!;
          const r = pos.row;
          const c = pos.col;

@@ -235,10 +208,7 @@
   return { B: territoryB, W: territoryW };
 }
 
-function determineWinner(
-  board: GoBoard,
-  capturedStones: { B: number; W: number },
-): Side | "draw" | null {
+function determineWinner(board: GoBoard, capturedStones: { B: number; W: number }): Side | "draw" | null {
   const counts = countStones(board);
   const territory = calculateTerritory(board);
 
@@ -271,13 +241,7 @@
   }
 
   if (cmd.action === "pass") {
-    const {
-      board,
-      currentSide,
-      playerNames,
-      capturedStones,
-      consecutivePasses,
-    } = cmd;
+    const { board, currentSide, playerNames, capturedStones, consecutivePasses } = cmd;
     const nextSide = getOpponent(currentSide);
     const counts = countStones(board);
     const newConsecutivePasses = consecutivePasses + 1;

diff --git a/src/core/plugin.ts b/src/core/plugin.ts
@@ -10,10 +10,7 @@ import { playGo } from "./logic";
 export { TOOL_NAME, TOOL_DEFINITION, SYSTEM_PROMPT } from "./definition";
 export { playGo } from "./logic";
 
-export const executeGo = async (
-  _context: ToolContext,
-  args: GoArgs,
-): Promise<ToolResult<never, GoState>> => {
+export const executeGo = async (_context: ToolContext, args: GoArgs): Promise<ToolResult<never, GoState>> => {
   try {
     let command: Command;
 
@@ -31,17 +28,8 @@ export const executeGo = async (
         playerNames: { B: blackPlayer, W: whitePlayer },
       };
     } else if (args.action === "move") {
-      if (
-        typeof args.row !== "number" ||
-        typeof args.col !== "number" ||
-        !args.board ||
-        !args.currentSide ||
-        !args.playerNames ||
-        !args.capturedStones
-      ) {
-        throw new Error(
-          "Move action requires row, col, board, currentSide, playerNames, and capturedStones parameters",
-        );
+      if (typeof args.row !== "number" || typeof args.col !== "number" || !args.board || !args.currentSide || !args.playerNames || !args.capturedStones) {
+        throw new Error("Move action requires row, col, board, currentSide, playerNames, and capturedStones parameters");
       }
       command = {
         action: "move",
@@ -53,16 +41,8 @@ export const executeGo = async (
         capturedStones: args.capturedStones,
       };
     } else if (args.action === "pass") {
-      if (
-        !args.board ||
-        !args.currentSide ||
-        !args.playerNames ||
-        !args.capturedStones ||
-        typeof args.consecutivePasses !== "number"
-      ) {
-        throw new Error(
-          "Pass action requires board, currentSide, playerNames, capturedStones, and consecutivePasses parameters",
-        );
+      if (!args.board || !args.currentSide || !args.playerNames || !args.capturedStones || typeof args.consecutivePasses !== "number") {
+        throw new Error("Pass action requires board, currentSide, playerNames, capturedStones, and consecutivePasses parameters");
       }
       command = {
         action: "pass",
@@ -80,8 +60,7 @@ export const executeGo = async (
 
     // Handle invalid move
     if (state.error) {
-      const isComputerTurn =
-        state.playerNames[state.currentSide] === "computer";
+      const isComputerTurn = state.playerNames[state.currentSide] === "computer";
 
       const instructions = isComputerTurn
         ? `Invalid move attempted. You must make a valid move. Choose an empty intersection where placing a stone would not result in immediate capture (suicide rule).`
@@ -99,10 +78,7 @@ export const executeGo = async (
     if (state.lastAction.type === "new_game") {
       message = "Started a new Go game on a 9x9 board! Black (●) goes first.";
     } else if (state.lastAction.type === "move") {
-      const captureMsg =
-        state.lastAction.captured > 0
-          ? ` and captured ${state.lastAction.captured} stone${state.lastAction.captured > 1 ? "s" : ""}`
-          : "";
+      const captureMsg = state.lastAction.captured > 0 ? ` and captured ${state.lastAction.captured} stone${state.lastAction.captured > 1 ? "s" : ""}` : "";
       message = `Played at (${state.lastAction.row}, ${state.lastAction.col})${captureMsg}.`;
     } else if (state.lastAction.type === "pass") {
       message = "Passed the turn.";
@@ -137,8 +113,7 @@ export const executeGo = async (
     console.error("ERR: exception\n Go game error", error);
     return {
       message: `Go game error: ${error instanceof Error ? error.message : "Unknown error"}`,
-      instructions:
-        "Acknowledge that there was an error with the Go game and suggest trying again.",
+      instructions: "Acknowledge that there was an error with the Go game and suggest trying again.",
     };
   }
 };

diff --git a/src/core/types.ts b/src/core/types.ts
@@ -56,10 +56,7 @@ export interface GoState {
   isTerminal: boolean;
   winner: Side | "draw" | null;
   consecutivePasses: number;
-  lastAction:
-    | { type: "new_game" }
-    | { type: "move"; row: number; col: number; captured: number }
-    | { type: "pass" };
+  lastAction: { type: "new_game" } | { type: "move"; row: number; col: number; captured: number } | { type: "pass" };
   error?: string;
 }