Initial commit

.env.example

@@ -0,0 +1,3 @@
+ENV=production
+SERVER_PORT=<SERVER_PORT>
+SERVER_MAX_CONCURRENCY=<SERVER_MAX_CONCURRENCY>

.github/workflows/go.yml

@@ -0,0 +1,23 @@
+# This workflow will build a golang project
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go
+
+name: Go
+on: [push, pull_request]
+
+jobs:
+    test:
+        strategy:
+            matrix:
+                go-version: [1.23.x]
+
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v4
+
+            - name: Set up Go
+              uses: actions/setup-go@v5
+              with:
+                  go-version: ${{ matrix.go-version }}
+
+            - name: Test
+              run: go test -cover -v ./...

.gitignore

@@ -0,0 +1,30 @@
+# Taken from URL: https://github.com/github/gitignore/blob/main/Go.gitignore
+# If you prefer the allow list template instead of the deny list, see community template:
+# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
+#
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# Go workspace file
+go.work
+go.work.sum
+
+# env file
+.env
+.env.production
+
+# Misc
+bin/

Dockerfile

@@ -0,0 +1,23 @@
+# See URL: https://hub.docker.com/_/golang
+# Use the Go image to build the binary only
+FROM golang:1.23.0 AS builder
+ENV CGO_ENABLED=0
+ENV GOOS=linux
+WORKDIR /go/src/public-holidays/
+COPY . .
+
+# Overwrite the development .env with the .env.production
+COPY .env.production .env
+
+RUN make
+
+# See URL: https://hub.docker.com/_/alpine
+# Use this image (~50MB) to run the "public-holidays", as the Go image contains too much bloat,
+# which isn't needed for running the application in production and the image which can be uploaded
+# to a public/private Docker register is then small
+FROM alpine:3.20.3
+
+COPY --from=builder /go/src/public-holidays/bin/* ./
+COPY --from=builder /go/src/public-holidays/.env ./
+EXPOSE 10000
+CMD ["./public-holidays"]

LICENSE

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2024 SoftwareSpot Apps
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Makefile

@@ -0,0 +1,22 @@
+# If the "VERSION" environment variable is not set, then use this value instead
+VERSION?=1.0.0
+TIME=$(shell date +%FT%T%z)
+GOVERSION=$(shell go version | awk '{print $$3}' | sed s/go//)
+
+LDFLAGS=-ldflags "\
+	-X github.com/softwarespot/public-holidays/internal/version.Version=${VERSION} \
+	-X github.com/softwarespot/public-holidays/internal/version.Time=${TIME} \
+	-X github.com/softwarespot/public-holidays/internal/version.User=${USER} \
+	-X github.com/softwarespot/public-holidays/internal/version.GoVersion=${GOVERSION} \
+	-s \
+	-w \
+"
+
+build:
+	@echo building to bin/public-holidays
+	@go build $(LDFLAGS) -o ./bin/public-holidays
+
+test:
+	go test -cover -v ./...
+
+.PHONY: build test

README.md

@@ -0,0 +1,209 @@
+# Public holidays
+
+![Go Tests](https://github.com/softwarespot/public-holidays/actions/workflows/go.yml/badge.svg)
+
+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](https://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
+
+```bash
+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.
+
+```json
+[
+    {
+        "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](https://en.wikipedia.org/wiki/Public_holidays_in_Denmark) |
+| 🇫🇮 Finland | FI                 | [Public Holidays in Finland](https://en.wikipedia.org/wiki/Public_holidays_in_Finland) |
+| 🇮🇸 Iceland | IS                 | [Public Holidays in Iceland](https://en.wikipedia.org/wiki/Public_holidays_in_Iceland) |
+| 🇳🇴 Norway  | NO                 | [Public Holidays in Norway](https://en.wikipedia.org/wiki/Public_holidays_in_Norway)   |
+| 🇸🇪 Sweden  | SE                 | [Public Holidays in Sweden](https://en.wikipedia.org/wiki/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](https://github.com/spf13/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)
+
+```bash
+cp .env.example .env
+cp .env.example .env.production
+```
+
+## Run not using Docker
+
+```bash
+go run .
+```
+
+or when using `make`
+
+```bash
+make
+
+./bin/public-holidays
+```
+
+### Version
+
+Display the version of the application and exit.
+
+```bash
+# As text
+./bin/public-holidays --version
+
+# As JSON
+./bin/public-holidays --json --version
+```
+
+### Help
+
+Display the help text and exit.
+
+```bash
+./bin/public-holidays --help
+```
+
+## Run using Docker
+
+1. Build the Docker image with the tag `public-holidays`.
+
+```bash
+docker build -t public-holidays .
+```
+
+2. Run the Docker image.
+
+```bash
+# 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.
+
+```bash
+# As text
+docker run --rm public-holidays --version
+
+# As JSON
+docker run --rm public-holidays --json --version
+```
+
+### Help
+
+Display the help text and exit.
+
+```bash
+docker run --rm public-holidays --help
+```
+
+## Tests
+
+Tests are written as [Table-Driven Tests](https://go.dev/wiki/TableDrivenTests).
+
+```bash
+go test -cover -v ./...
+```
+
+or when using `make`
+
+```bash
+make test
+```
+
+### Linting
+
+Docker
+
+```bash
+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
+
+```bash
+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](https://opensource.org/license/mit) license.

cmd/execute.go

@@ -0,0 +1,28 @@
+package cmd
+
+import (
+	"flag"
+
+	"github.com/softwarespot/public-holidays/internal/logging"
+)
+
+func Execute(_ []string, logger logging.Logger) error {
+	var showHelp bool
+	flagBoolVarP(&showHelp, "help", "h", false, "Display the help text and exit")
+
+	var showVersion bool
+	flagBoolVarP(&showVersion, "version", "v", false, "Display the version of the application and exit")
+
+	var asJSON bool
+	flagBoolVarP(&asJSON, "json", "j", false, "Output the result as JSON")
+	flag.Parse()
+
+	if showHelp {
+		cmdHelp()
+		return nil
+	}
+	if showVersion {
+		return cmdVersion(asJSON)
+	}
+	return cmdServer(logger)
+}

cmd/help.go

@@ -0,0 +1,18 @@
+package cmd
+
+import "fmt"
+
+func cmdHelp() {
+	helpText := `Usage: ./public-holidays [OPTIONS]
+
+Start the public holidays API.
+
+Options:
+  -h, --help      Show this help text and exit.
+  -v, --version   Display the version of the application and exit.
+  -j, --json      Output the version as JSON.
+
+Examples:
+  ./public-holidays`
+	fmt.Println(helpText)
+}