Ten Pin Scoring

Maker's Academy: Week 5 Challenge

In javascript, count and sum the scores of a bowling game of one player

Spec

A bowling game consists of 10 frames in which the player tries to knock down the 10 pins.

Frames:

• In every frame the player can throw 1 or 2 times. The number depends on whether a strike was thrown on the first throw.
• The score of a frame is the number of knocked down pins, plus bonuses for strikes and spares.
• After every frame the pins are reset

Strikes:

• The player has a strike if he knocks down all 10 pins with the first roll in a frame.
• The frame ends immediately
• The bonus for that frame is the number of pins knocked down by the next 2 rolls - the next frame (expect if the player rolls a strike agian.

Spares:

• The player has a spare if they knock down all 10 pins within the 2 rolls of a frame.
• The bonus for that frame is the number of pins knocked down by the next roll.

10th frame:

• If the player rolls a strike or spare in the 10th frame he can roll the additional balls for the bonus. But he can never have more than 3 rolls in the 10th frame.
• The additional rolls only count for the bonus, not for the regular frame count.
• Example 1: 10, 10, 10 in the 10th frame gives 30 points (10 points for the regular strike, and 20 points for the bonus
• Example 2: 1, 9, 10 in the 10th frame gives 20 points (10 points for the regular spare and 10 points for the bonus)

Special games:

• A gutter game is when the player never hits a pin (20 zero scores)
• A perfect game is when the player rolls 12 strikes - scoring 300 points.

###Tools

• GitHub for version control
• Javascript
• Jasmine for testing
• Google Chrome for running/viewing Jasmine tests

###Personal Goals:

• TDD, fully test everything.
• Refactoring for clean code.
  • In particular, applying single responsibility principles.
• Mindful programming: No randomly hacking at problems, but conciously considoring why soemthing is failing, and what the expect consequence of an action will be.

Code Snippets

Game.prototype.calculateGameScore = function() {
	this.collateFrameScores();
	this.gameScore = this.frameScores.reduce(function(a,b) {
		return a + b;
	});
	return this.gameScore;
};

Refactoring:

Before:

Frame.prototype.calculateBonusScore = function() {
	if ( this.isStrike() && this.nextFrameIndex() !==9 ) {
		if (this.nextFrameFirstThrow() !== 10) {
			this.strikeStandardBonus();
		} else {
			this.doubleStrikeBonus();
		}
	} else if ( this.isStrike() && this.nextFrameIndex() === 9) {
			this.strikeStandardBonus();
	} else if (this.isSpare()) {
			this.spareBonus()
		}
	return this.bonusScore;
};

After:

Frame.prototype.calculateBonusScore = function() {
	if ( this.isStrike() ) {
		this.strikeBonusCalc();
		} else if (this.isSpare() ){
			this.spareBonus();	}
			return this.bonusScore;
		};


Frame.prototype.strikeBonusCalc = function() {
	if ( this.isNextFrameStrike() && this.whatFrame() !== 8 ) {
		this.doubleStrikeBonus();
		} else {
			this.strikeStandardBonus();
		}
	};