Poker evaluator

This project showcases my proficiency in Go by creating a clear and readable poker hand evaluator. The primary focus is on writing clean, maintainable code that effectively demonstrates the logic behind evaluating various poker hands.

Game play

• Provide 2 poker hands with 5 cards in each hand.
• Each card must start with the rank and then the suit e.g. 5C as in the 5 of Clubs.
• Cards are case-insensitive. Therefore, aH is the same as Ah or AH.

Ranks (values)

• 2-9 are the same, e.g. 2 or 8
• 10 is T
• Jack is J
• Queen is Q
• King is K
• Ace is A

Suits

• Clubs are C
• Diamonds are D
• Hearts are H
• Spades are S

Prerequisites

• Go 1.23.0 or above
• make (if you want to use the Makefile provided)
• Docker

Dependencies

IMPORTANT: No 3rd party dependencies are used.

I could easily use Cobra (and usually I do, because it allows me to write powerful CLIs), but I felt it was too much for such a tiny project. I only ever use dependencies when it's say an adapter for an external service e.g. Redis, MySQL or Prometheus.

Run not using Docker

go run . "AH AC AD QC QD" "QD QH QC AD AC"

Output the result as JSON, instead of text

go run . --json "AH AC AD QC QD" "QD QH QC AD AC"

or when using make

make

# As text
./bin/poker-evaluator "AH AC AD QC QD" "QD QH QC AD AC"

# As JSON
./bin/poker-evaluator --json "AH AC AD QC QD" "QD QH QC AD AC"

Version

Display the version of the application and exit.

# As text
./bin/poker-evaluator --version

# As JSON
./bin/poker-evaluator --json --version

Help

Display the help text and exit.

./bin/poker-evaluator --help

Run using Docker

1. Build the Docker image with the tag poker-evaluator.

docker build -t poker-evaluator .

2. Run the Docker image with the provided arguments.

# As text
docker run --rm poker-evaluator "AH AC AD QC QD" "QD QH QC AD AC"

# As JSON
docker run --rm poker-evaluator --json "AH AC AD QC QD" "QD QH QC AD AC"

Version

Display the version of the application and exit.

# As text
docker run --rm poker-evaluator --version

# As JSON
docker run --rm poker-evaluator --json --version

Help

Display the help text and exit.

docker run --rm poker-evaluator --help

Tests

Tests are written as Table-Driven Tests.

go test -cover -v ./...

or when using make

make test

Coverage

For the poker package (found under internal), the test coverage is about 97%. This isn't to say there aren't any "bugs" 😀, but that it's better than 0% and is an indication that it's passing the Poker rules.

go test -cover -v github.com/softwarespot/poker-evaluator/internal/poker

Linting

Docker

docker run --rm -v $(pwd):/app -w /app golangci/golangci-lint:latest golangci-lint run -v --tests=false --disable-all -E durationcheck,errorlint,exhaustive,gocritic,gosimple,ineffassign,misspell,predeclared,revive,staticcheck,unparam,unused,whitespace --max-issues-per-linter=10000 --max-same-issues=10000

Local

golangci-lint run --tests=false --disable-all -E durationcheck,errorlint,exhaustive,gocritic,gosimple,ineffassign,misspell,predeclared,revive,staticcheck,unparam,unused,whitespace --max-issues-per-linter=10000 --max-same-issues=10000

Additional information

This section documents any additional information which might be deemed important for the reviewer.

Decisions made

• Despite using 1.23.0+ and the slices pkg being available, I have opted not to use it, and instead went for how I've been writing Go code before the slices pkg existed. Although for production code, I have started to use it where applicable.
• I haven't used an assertion library, as I have never used one in production code and have opted for creating my own simple test helpers.
• The Hand.Compare() func returns an int as an alias type of Winner, as I thought since it returns 3 exclusive values, that it should be similar to that of [https://pkg.go.dev/cmp#Compare].
• Naming is hard, so I have tried my best to name funcs, structs, variables etc... as best I can.

Project setup

Commands used to setup the project's directory.

mkdir poker-evaluator
cd poker-evaluator
go mod init github.com/softwarespot/poker-evaluator
touch README.md
touch LICENSE
touch Dockerfile

License

The code has been licensed under the MIT license.