initial commit

.gitignore

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+node_modules
+.DS_STORE
+tensorboard_logs
+dist
+.vscode

CONTRIBUTING.md

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+# How to Contribute
+
+We are not currently accepting external code contributions to this project. Please feel free to file bugs using GitHub's issue tracker."

README.md

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+# Tic-Tac-Toe the Hard Way
+
+This repository contains code to accompany the podcast ["Tic-Tac-Toe the Hard Way"](https://pair.withgoogle.com/thehardway).
+
+The code provided here is offered as is purely for illustrative purposes for particularly adventurous listeners.
+There are two authors for the code in this repository:
+ - David: A writer
+ - Yannick: A software engineer
+
+The code is provided with minimal changes or cleanup from how it was originally
+written while exploring the topics in the podcast, this is to encourage anyone
+just getting started, its okay if your code doesn't look perfect!
+
+This repository acts primarily as accompanying documentation for the podcast and
+will remain as is.
+
+> We will not be accepting contributions to this project.
+
+## Requirements & Setup
+
+You will generally need to be comfortable with JavaScript and Node.js to make use
+of these repository. If that is not you (and even if it is) we encourage you to
+checkout the podcast itself at https://pair.withgoogle.com/thehardway.
+
+There are READMEs the subfolders with further instructions if you are interested in running the code we wrote:
+ - tic-tac-toe: Contains all the code for the tic-tac-toe experiment
+    - `tic-tac-toe/training` contains all the training code.
+    - `tic-tac-toe/viewer` contains all the viewer code.
+ - tic-tac-__two__: Contains all the code for the tic-tac-two experiment
+    - `tic-tac-two/training` contains all the training code.
+    - `tic-tac-two/viewer` contains all the viewer code.
+
+Before running any of the code in those subfolders you should run `npm install` or `yarn` in this folder.
+
+> __This is not an official Google product.__

package.json

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+{
+  "name": "tic-tac-two",
+  "version": "1.0.0",
+  "main": "index.js",
+  "private": true,
+  "dependencies": {
+    "clang-format": "^1.4.0",
+    "typescript": "3.5.3"
+  }
+}

tic-tac-toe/README.md

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+# Tic-tac-toe experiment
+
+## Training the models
+
+### David's agent
+
+- Install dependencies: run `npm install`
+- Generate data and train model: run `npm run generate-and-train`
+
+This will a new folder in the `models/` directory with the saved model. This output can be used in the [viewer](viewer)
+
+### Yannick's agent
+
+- Install dependencies: run `npm install`
+- Train model: run `npm run train`
+
+This will a new folder in the `models/` directory with the saved model. This output can be used in the [viewer](viewer)
+
+Training will also write out some metrics to a tensorboard logdir.
+
+Yannick's training code is currently setup to use tfjs-node-gpu. Which requires a
+linux machine with CUDA to run. If you want to run this on a machine without CUDA
+(e.g. mac or windows), just replace tfjs-node-gpu with tfjs-node wherever you see it.
+
+## Seeing the results
+
+The [viewer](viewer) folder contains a simple web app to see the results of the game. To see it, launch a webserver in this folder. e.g.
+
+```
+python -m SimpleHTTPServer 8000
+```
+
+Then go to `localhost:8000/viewer` in your browser.
+
+If you want to change the model loaded by each agent in the viewer, edit _david_agent.js_ or _yannick_agent.js_ respectively.

tic-tac-toe/shared/agent.js

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+/**
+ * @license
+ * Copyright 2020 Google LLC. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+
+export class AbstractAgent {
+  /**
+   * Creates an agent that can play
+   * options is of the form: { symbol: 'x' }
+   */
+  constructor(options) {
+    this.symbol = options.symbol;
+    this.name = options.name || this.constructor.name;
+  }
+
+  /**
+   * An initialization function that can be used to load state that may
+   * take a while to complete.
+   */
+  async init() {
+    return;
+  }
+
+  /**
+   * Takes a boardState and returns a move. A move is an object
+   * of the form {symbol: 'x'|'o', position: number}
+   * @param {Object} boardState
+   * @returns {symbol: 'x'|'o', position: number} move
+   */
+  move(boardState) {}
+}

tic-tac-toe/shared/game_utils.js

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+/**
+ * @license
+ * Copyright 2020 Google LLC. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+
+export const BOARD_EMPTY_VAL = -1;
+
+export function checkForWinner(boardState) {
+  const rows = 3;
+  const cols = 3;
+  const stride = 3;
+
+  function checkCells(boardState, indices) {
+    const cell1 = boardState[indices[0]];
+    const cell2 = boardState[indices[1]];
+    const cell3 = boardState[indices[2]];
+
+    if (cell1 != -1 && cell1 === cell2 && cell2 === cell3) {
+      return {
+        hasWinner: true, winningSymbol: cell1, winningCells: indices,
+      }
+    } else {
+      return {
+        hasWinner: false,
+      }
+    }
+  }
+
+  // Check the rows
+  for (let i = 0; i < (rows * stride); i += stride) {
+    const indices = [
+      i,
+      i + 1,
+      i + 2,
+    ];
+    const result = checkCells(boardState, indices);
+    if (result.hasWinner) {
+      return result;
+    }
+  }
+
+  // Check the columns
+  for (let i = 0; i < cols; i++) {
+    const indices = [
+      i,
+      i + stride,
+      i + (stride * 2),
+    ];
+    const result = checkCells(boardState, indices);
+    if (result.hasWinner) {
+      return result;
+    }
+  }
+
+  // Check Diagonal 1, [0,0], [1,1], [2,2];
+  {
+    const indices = [
+      0,
+      1 + (1 * stride),
+      2 + (2 * stride),
+    ];
+    const result = checkCells(boardState, indices);
+    if (result.hasWinner) {
+      return result;
+    }
+  }
+
+  // Check Diagonal 2, [0,2], [1,1], [2,0],
+  {
+    const indices = [
+      stride - 1,
+      1 + (1 * stride),
+      0 + (2 * stride),
+    ];
+
+    const result = checkCells(boardState, indices);
+    if (result.hasWinner) {
+      return result;
+    }
+  }
+
+  return {
+    hasWinner: false,
+  };
+}
+
+export function checkForIllegalMove(boardState, move) {
+  if (boardState[move.position] !== BOARD_EMPTY_VAL || move.position < 0 ||
+      move.position > 8) {
+    return {
+      hasError: true,
+      errorCell: move.position,
+    };
+  }
+
+  return {
+    hasError: false,
+  };
+}
+
+export function checkDone(boardState) {
+  const isDone = boardState.every(symbol => symbol != -1);
+  return isDone;
+}
+
+export async function wait(time) {
+  return new Promise(resolve => {
+    setTimeout(() => {
+      resolve();
+    }, time);
+  });
+}

tic-tac-toe/shared/random_agent.js

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+/**
+ * @license
+ * Copyright 2020 Google LLC. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+
+import {AbstractAgent} from './agent.js';
+
+export class RandomAgent extends AbstractAgent {
+  constructor(options) {
+    super(options);
+  }
+
+  move(boardState) {
+    const freeIndices = boardState.reduce((memo, val, idx) => {
+      if (val === -1) {
+        memo.push(idx);
+      }
+      return memo;
+    }, []);
+
+    if (freeIndices.length === 0) {
+      throw new Error('No legal moves');
+    }
+
+    // Select an index to play.
+    const nextIndex = Math.floor(Math.random() * freeIndices.length);
+    return {
+      symbol: this.symbol,
+      position: freeIndices[nextIndex],
+    };
+  }
+}