First attempt at RPS kata

dcRpsSpec.js

/**
 * Created by pivotal on 6/14/17.
 *  new Rps().play(...)
 */

function Rps() {
    this.p1WinConditions = {
        scissors: "paper",
        paper: "rock",
        rock: "scissors"
    };
    this.validThrows = Object.keys(this.p1WinConditions);

    this.play = function (p1, p2, ui) {
        if (this.anyInvalidThrows(p1, p2))
            return ui.renderInvalid();
        if (p1 === p2) return ui.renderTie();
        this.p1WinConditions[p1] == p2
            ? ui.renderP1Wins()
            : ui.renderP2Wins();
    };

    this.anyInvalidThrows = function (p1, p2) {
        return !(this.validThrows.includes(p2) &&
                 this.validThrows.includes(p1));
    }
};

describe("play", function () {
    var ui = null;
    beforeEach(function () {
        ui = jasmine.createSpyObj("ui", ["renderP1Wins", "renderP2Wins",
            "renderTie", "renderInvalid"]);
    });

    it("rock v scissors", function () {
        const rps = new Rps().play("rock", "scissors", ui);
        expect(ui.renderP1Wins).toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("rock v paper", function () {
        const rps = new Rps().play("rock", "paper", ui);
        expect(ui.renderP2Wins).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("scissors v paper", function () {
        const rps = new Rps().play("scissors", "paper", ui);
        expect(ui.renderP1Wins).toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("scissors v rock", function () {
        const rps = new Rps().play("scissors", "rock", ui);
        expect(ui.renderP2Wins).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("paper v scissors", function () {
        const rps = new Rps().play("paper", "scissors", ui);
        expect(ui.renderP2Wins).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("paper v rock", function () {
        const rps = new Rps().play("paper", "rock", ui);
        expect(ui.renderP1Wins).toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("rock v rock", function () {
        const rps = new Rps().play("rock", "rock", ui);
        expect(ui.renderTie).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("paper v paper", function () {
        const rps = new Rps().play("paper", "paper", ui);
        expect(ui.renderTie).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("scissors v scissors", function () {
        const rps = new Rps().play("scissors", "scissors", ui);
        expect(ui.renderTie).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderInvalid).not.toHaveBeenCalled();
    });

    it("scissors v sailboat", function () {
        const rps = new Rps().play("scissors", "sailboat", ui);
        expect(ui.renderInvalid).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
    });

    it("sailboat v paper", function () {
        const rps = new Rps().play("sailboat", "paper", ui);
        expect(ui.renderInvalid).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
    });

    it("sailboat v sailboat", function () {
        const rps = new Rps().play("sailboat", "sailboat", ui);
        expect(ui.renderInvalid).toHaveBeenCalled();
        expect(ui.renderP1Wins).not.toHaveBeenCalled();
        expect(ui.renderP2Wins).not.toHaveBeenCalled();
        expect(ui.renderTie).not.toHaveBeenCalled();
    });

});