TalangHT21_TDD: Bowling

Prerequisites

• .Net Core SDK 5.x
• Any IDE (Rider, VSCode, VisualStudio are recommended)
• MiniCover
  • dotnet tool install --global minicover

Usage

• To run test
  • dotnet test or "watch it" with: dotnet watch test --project BowlingTest
• To generate coverage report
  • ./run_minicover.sh
• The API can be found at: http://localhost:5000/swagger/index.html

The assignment

• You are to implement a bowling game using TDD methodology. If you are unfamiliar the rules of bowling, here is an explanation: https://en.wikipedia.org/wiki/Ten-pin_bowling#Scoring
• For this excersise I want you write integration tests first, then digg your way down to unit tests
  • The game should be playable via REST API (a partial implementation is provided in the example).

Requested functionality

• GET /start will start a new initialized score card and reset the game
• GET /state will return the current state of the game
• POST /roll will:
  • roll a bowling ball, hitting a random number of pins
  • if it is the first throw in the frame and it does not hit all pins, write the number of pins
  • if it is the first throw in the frame and it does hit all pins, write an X (strike) and move to the next frame
  • if it is the second throw and you don't hit all pins, write the number of pins, move to the next frame
  • if it is the second throw and you hit all remaining pins, write an / (spare), move to the next frame
  • calculate the points per frame:
    • spare adds the number for the next throw on top
    • strike adds the number for the next frame on top
  • When all throws are done, rolling a new throw should return HTTP 400 with a descriptive error

The rules of TDD are:

• You have to write the test first using the Red-Green-Refactor process
  • You are not allowed to write ANY production code until you have a failing test (Red state)
  • You are only allowed to write the absolute minimum amount of production code to repair the test (Green state)
  • If applicable you are allowed to rearrange the production code, but not allowed to change the logic. (Refactor state)
  • Repeat the Red state
• A test is only allowed to test ONE functionality
  • Use the least amount of asserts needed to verify the functionality
• If different test cases only differ on data, consider using a parameterized test
• Unit tests don't contain any infrastructure, they only test logic/flow
• Integration tests don't contain exhaustive logic tests. They only test happy flow or relevant alternative flows.
  • Integration tests don't use mocks (unless totally unavoidable)