RockPaperScissors - an overengineered and charmingly rude JavaScript rock paper scissors game that I wrote when I was bored.

rock-paper-scissors.js

;(function () {

  var RockPaperScissors = function (opts) {
    this.opts = opts ? opts : {};
    this.scoreboard = [];
    this.choices = [];

    this.truthtable = this.opts.truthtable || {
      rock: ['scissors'],
      paper: ['rock'],
      scissors: ['paper']
    };

    this.messages = {
      prompt: 'Rock, paper, scissors? Pick one:',
      afterWin: 'You win. Nicely done, you filthy bastard.',
      afterLoss: 'You lose. Serves you right, asshole!',
      afterTie: "It's a tie! Holy fuck.",
      playAgain: 'Would you like to play again? Y or N',
      invalidAnswer: "That wasn't one of the options, dummy."
    };

    this.init = function () {
      this.populateChoices();
      this.playRound();
    };

    this.playRound = function () {
      var choice = this.promptPlayer();

      if (this.isValidAnswer(choice)) {
        this.announceWinner(choice, this.pickRandomChoice());
      } else {
        alert(this.messages.invalidAnswer);
      }
      if (prompt(this.messages.playAgain) === 'Y') {
        return this.playRound();
      }
      alert('Goodbye!');
    };

    this.pickRandomChoice = function () {
      var i = Math.floor(Math.random() * this.choices.length);
      return this.choices[i];
    };

    this.promptPlayer = function () {
      return prompt(this.messages.prompt).toLowerCase();
    };

    this.isValidAnswer = function (answer) {
      return this.choices.indexOf(answer) !== -1;
    };

    this.populateChoices = function () {
      this.choices = Object.keys(this.truthtable);
    };

    this.xBeatsY = function (x, y) {
      return this.truthtable[x].indexOf(y) !== -1;
    };

    this.announceWinner = function (playerChoice, computerChoice) {
      var message = 'The computer picked ' + computerChoice + '...\n\n';
      if (playerChoice === computerChoice) {
        return alert(message + this.messages.afterTie);
      }
      if (this.xBeatsY(playerChoice, computerChoice)) {
        return alert(message + this.messages.afterWin);
      }
      return alert(message += this.messages.afterLoss);
    };

    this.init();
  };

  window.RockPaperScissors = RockPaperScissors;

})();