erickrawczyk / minesweeper

Simplified Minesweeper API

Minesweeper API

This repo contains a GraphQL API for a simplified version of minesweeper. It exposes a Game type and a Square type, as well as mutations to create a game and select a square. The GraphQL playground is enabled and can be explored at https://minesweeper.kraw.cz/graphql

Local Development

Prerequisites

• Yarn v1.13+
• Node v12+
• Docker v19+, if building images locally
• Terraform v0.12+, if deploying infrastructure locally

Application Setup

• Run yarn to install dependencies and copy .env.example into .env
• Populate .env with proper values for the DB. This file is only for simplified local development; In production, CI pulls the values from AWS Secrets Manager
• Run yarn start to start a local express server on port 8080.

Infrastructure Setup

• Enter the terraform directory
• Run terraform init to initialize terraform
• Run terraform plan to review infrastructure changes
• Run terraform apply to deploy those changes

Usage

The GraphQL endpoints can be queried at https://minesweeper.kraw.cz/graphql. The playground contains tabs for types in the Schema, as well as available Queries and Mutations.

Example queries and mutations have been provided here for simplicity, but most properties can be omitted from the response.

Creating a game

The createGame mutation accepts two arguments, width and height, with integer values between 2 and 50 and returns a Game object.

Request

mutation {
  createGame(width: 5, height: 5) {
    id
    createdAt
    modifiedAt
    completedAt
    height
    width
    result
    board {
      id
      gameId
      selected
      hasBomb
      x
      y
      adjacentBombs
    }
  }
}

Response

{
  "data": {
    "createGame": {
      "id": "151c381b-3234-4610-9826-745d3f5afcf0",
      "createdAt": "2019-10-27T00:20:12.480Z",
      "modifiedAt": "2019-10-27T00:20:12.480Z",
      "completedAt": null,
      "height": 5,
      "width": 5,
      "result": null,
      "board": [
        [
          {
            "id": "56eaee12-6bed-4f5f-8cab-85be1e71e330",
            "gameId": "151c381b-3234-4610-9826-745d3f5afcf0",
            "selected": false,
            "hasBomb": false,
            "x": 0,
            "y": 0,
            "adjacentBombs": 0
          },
          ...
        ]
      ]
    }
  }
}

Selecting a Square

The move mutation accepts three arguments, a uuid gameId, and integer values x and y and returns a Game object.

If the user selects a bomb or the last non-bomb square, the game will end and contain a result and a completedAt attribute.

Request

mutation {
  move(gameId: "151c381b-3234-4610-9826-745d3f5afcf0", x: 2, y: 3) {
    modifiedAt
    completedAt
    result
    board {
      hasBomb
      selected
      adjacentBombs
    }
  }
}

Response

{
  "data": {
    "move": {
      "modifiedAt": "2019-10-27T00:20:12.480Z",
      "completedAt": null,
      "result": null,
      "board": [
        [
          {
            "hasBomb": false,
            "selected": false,
            "adjacentBombs": 0
          },
          {
            "hasBomb": false,
            "selected": false,
            "adjacentBombs": 0
          },
          ...
        ]
      ]
    }
  }
}

Listing Games

There are no arguments for the games query. This example is only requesting a few properties, although any properties of the Game schema can be requested.

Request

query {
  games {
    id
    width
    height
    createdAt
    result
  }
}

Response

{
  "data": {
    "games": [
      {
        "id": "334cfdb9-a1c3-45df-bbc1-754de27e78eb",
        "width": 5,
        "height": 5,
        "createdAt": "2019-10-26T23:02:20.801Z",
        "result": "WON"
      },
      ...
    ]
  }
}

Project Layout

The application server entrypoint is in main.js (index.js just contains esm). It uses Apollo for the GraphQL server, and the schema folder separates each resource into separate files. lib contains database

The infrastructure code is stored in the terraform folder. Most of the files are separated by service, although autoscaling, security, and networking are grouped by functionality instead. The application is Dockerized and shipped on AWS Fargate through CircleCI.

Roadmap

• Improve the mechanism to determine bomb distribution. The current random implementation could lead to unsolvable and/or boring games.

• Improve the board-drawing algorithm, potentially adding a Board type to both GraphQL and Postgres. The separation of concerns between Game and Square are blurred, and the algorithm is too mutative.

• Improve db mocking, as the current implementation isn't flexible enough to handle multiple db calls effectively

• Set up a branch workflow in CI that will deploy feature branches to a separate cluster for testing

• Expose a query for the Square type, and add filter arguments for the games query.

• Oh, and a frontend