Overview

A rest service to play the game Rock, Paper, Scissors. A front-end application picks up a shape of the game and then call this service to the GET endpoint /play and passing the selected shape through the query string parameter withPlayerMove.

Player selected shape must be one of rock, paper or scissors. Failing to pass a valid shape will result in a 400 Bad Request.

The service then will randomly generate a shape as service move and will decide who win the match. The response will have the following properties:

• winner: the winner of the game if there is one (could be tie), either player 1 or `player 2``
• tie: true if the 2 players played the same shape (e.g. rock vs rock). This field is mutually exclusive with winner
• message: the result message of the game (e.g. paper beats rock)
• moves: an object representing the moves of player 1 and player 2

Response example in case of a winner

{ 
  winner: 'player2', 
  message: 'paper beats rock', 
  moves: { 
    player1: 'rock', 
    player2: 'paper' 
  } 
}

Response example in case of a tie

{ 
  tie: true, 
  message: 'Tie!', 
  moves: { 
    player1: 'rock', 
    player2: 'rock' 
  } 
}

Service architecture

The service is designed to run as a serverless function in AWS Lambda triggered by API Gateway endpoint.

Deployment

Install serverless framework and configure your serverless profile (you will need to provide an AWS programmatic access key and password with AWSLambdaFullAccess and IAMFullAccess roles).

Configure your default profile:

serverless config credentials --provider aws --key $AWS_ACCESS_KEY_ID --secret $AWS_SECRET_ACCESS_KEY

Run:

serverless deploy

At the end of the deploy you will be provided with the API Gateway endpoints that will trigger the function.