github.com/softwarespot/public-holidays

Public holidays

This project showcases my proficiency in Go by creating a clear and readable public holidays API. The primary focus is on writing clean, maintainable code that effectively demonstrates the logic behind retrieving public holidays for a country's ISO 3166-1 alpha-2 code.

GET /holidays/v1/{country}/{year}

This endpoint retrieves a list of public holidays for a specified country and year. By replacing {country} with the two-letter ISO 3166-1 alpha-2 code of the desired country and {year} with the target year, users can access detailed information about each holiday, including dates, local names and English names. This API is useful for applications that need to display or utilize holiday data for various purposes, such as scheduling or planning.

Hosted by render.com

This API is available at https://public-holidays.onrender.com.

IMPORTANT The instance might be down due to inactivity, therefore, wait about 50s for the instance to be started again.

Example request

curl -s "https://public-holidays.onrender.com/holidays/v1/FI/2024" | jq

# or locally

curl -s "http://localhost:10000/holidays/v1/FI/2024" | jq

Response format

The response will be in JSON format and includes an array of holiday objects with the following details:

• date: The date of the holiday.
• name: The name of the holiday in the local language.
• englishName: The name of the holiday in English.

[
    {
        "date": "2024-01-01",
        "name": "Uudenvuodenpäivä",
        "englishName": "New Year's Day"
    },
    {
        "date": "2024-01-06",
        "name": "Loppiainen",
        "englishName": "Epiphany"
    },

    ...
]

Countries

Here is a list of the supported countries.

Country	ISO 3166-1 alpha-2	Wikipedia Link
🇩🇰 Denmark	DK	Public Holidays in Denmark
🇫🇮 Finland	FI	Public Holidays in Finland
🇳🇴 Norway	NO	Public Holidays in Norway
🇸🇪 Sweden	SE	Public Holidays in Sweden

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.

Setup

1. Create and edit the .env (used when developing locally) and .env.production (used when deploying to production)

cp .env.example .env
cp .env.example .env.production

Run not using Docker

go run .

or when using make

make

./public-holidays-cli

Version

Display the version of the application and exit.

make

# As text
./public-holidays-cli --version

# As JSON
./public-holidays-cli --json --version

Help

Display the help text and exit.

make

./public-holidays-cli --help

Run using Docker

1. Build the Docker image with the tag public-holidays.

docker build -t public-holidays .

1. Run the Docker image.

# Port number should the same as defined in ".env.production"
docker run -p "10000:10000" --rm public-holidays

Version

Display the version of the application and exit.

# As text
docker run --rm public-holidays --version

# As JSON
docker run --rm public-holidays --json --version

Help

Display the help text and exit.

docker run --rm public-holidays --help

Tests

Tests are written as Table-Driven Tests.

go test -cover -v ./...

or when using make

make test

Coverage

go test -cover -v github.com/softwarespot/public-holidays/internal/

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.
• Loosely used https://jsonapi.org/.

License

The code has been licensed under the MIT license.