TDD Rediscovered ProgrammerTests Exercise
The Exercise
The Bowling Game Kata
Inspired by Ron Jeffries
The idea is to create a console application that can calculate the traditional score for a Ten-Pin Bowling game.
- A game consists of ten frames.
- A frame consists of two tries to knock down ten pins.
- If the bowler knocks down less than ten pins, that is their score
- if the bowler knocks down ten pins in two tries, this is a 'spare', and their score is ten + the pins knocked down in the first try from the next frame.
- If the bowler knocks down ten pins in one try, this is a 'strike', and thier score is ten + the pins knocked down in the next frame
- If the bowler gets a 'spare' on the last frame, they get an additional try, and their score is ten + the number of pins knocked down
- If the bowler gets a 'strike' on the last frame, they get an additional two tries, and their score is ten + the number of pins knocked down
- On any extra tries in the last frame, knocking all the pins down does not count as a 'spare' or a 'strike'
And some scope control
- We are just calculating the final total, we don't calculate the score for intermediate frames
- We do not check for valid rolls (i.e. -1 or 11)
- We don't check the input for additional frames or rolls
For information, the score will be between 0 and 300.
The Rules
The purpose of this kata is to experience the TDD approach whilst using the following rules:
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We are writing Programmer Tests. A failing test tells us that the last edit to the source is the source of an issue
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The prompt to write a test is a new requirement. We assume that we obtained these when elaborating the story with the customer.
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When we discover that we need new collaborators by refactoring we ask: are they part of our public interface or an implementation detail. We don’t test implementation details