tennis refactoring kata solution

tennis_1_refactored.js

var TennisGame1 = function(player1Name, player2Name) {
    this.scores = [
      0,
      0
    ];

    this.players = [
        player1Name,
        player2Name
    ];

    this.hyphen = '-';
    this.whiteSpace = ' ';
};

TennisGame1.prototype.isDraw = function() {
    return this.scores[0] === this.scores[1];
};

TennisGame1.prototype.isDeuce = function() {
    return this.scores[0] >= 3 && this.isDraw();
};

TennisGame1.prototype.isEndGame = function() {
    return Math.max(this.scores[0], this.scores[1]) >= 4;
};

TennisGame1.prototype.pointCode = function(playerIndex) {
    if (playerIndex === 1 && this.isDraw()) {
        return 'All';
    }

    return [
      'Love',
      'Fifteen',
      'Thirty',
      'Forty'
    ][this.scores[playerIndex]];
};

TennisGame1.prototype.getPlayerInAdvance = function() {
    if (this.scores[0] > this.scores[1]) {
        return this.players[0];
    }

    return this.players[1];
};

TennisGame1.prototype.getWinSituation = function() {
    if (this.isAdvantage()) {
        return 'Advantage';
    }

    return 'Win for';
};

TennisGame1.prototype.isAdvantage = function() {
    return Math.abs(this.scores[0] - this.scores[1]) === 1;
};

TennisGame1.prototype.wonPoint = function(playerName) {
    this.scores[this.players.indexOf(playerName)] += 1;
};


TennisGame1.prototype.getScore = function() {
    var score;

    if (this.isDeuce()) {
        score = 'Deuce';
    } else if (this.isEndGame()) {
        score = this.getWinSituation() + this.whiteSpace + this.getPlayerInAdvance();
    } else {
        score = this.pointCode(0) + this.hyphen + this.pointCode(1);
    }

    return score;
};

if (typeof window === "undefined") {
    module.exports = TennisGame1;
}