App is live at https://bowling-score-api.herokuapp.com/
(Usage info is mentioned at the root path /)
create a new game:
POST /games
note the id in the response
record a new ball played:
POST /games/:game_id/new_ball
see game score with breakdown
GET /games
git clone the repository
run bundle inside the dir
setup the database:
create the postgres user:
postgres=# create user rails with password 'rails';
postgres=# alter role rails superuser createrole createdb replication;
create the database and set the schema:
$ rails db:setup
run the server:
$ rails server
run the tests:
$ rails test
This is a rails api to keep track of bowling games.
Multiple games can be played simultaneously. Any number of games can be created.
The game id (which is a UUID) serves as a secret token. Only users who have this
token can update the game, and see the progress.
Due to the complicated nature of scoring of bowling game, there is a lot of business logic; hence a lot of unit tests.
I tried to keep a simple architecture:
-
In the database only the pins that were dropped are stored. Rest all of the score information can be calculated based on this data
-
All necessary validations are performed (pins must be between 0 and 10, game is not completed) when a new ball play is recorded
Almost all the business logic (actions on new ball, score calculation) is performed inside the Game model.
I avoided cyclic dependencies, by making sure that Game calls Frame, and not vice-versa.
Game -> Frame
Same for, Frame -> Ball
The app looked simple on the outside but I quickly ran into a lot of corner cases to
-
record a new ball played
-
calculate the score
I relied on TDD. Created my tests and made them pass one by one, and gradually an architecture emerged.