use an enum for supported countries with the related ISO code

src/Actions/Belgium.php

@@ -7,33 +7,29 @@
 
 class Belgium implements Executable
 {
-    protected int $year;
-
     public function execute(int $year): array
     {
-        $this->year = $year;
-
-        $this->ensureYearCanBeCalculated();
+        $this->ensureYearCanBeCalculated($year);
 
-        $fixedHolidays = $this->fixedHolidays();
-        $variableHolidays = $this->variableHolidays();
+        $fixedHolidays = $this->fixedHolidays($year);
+        $variableHolidays = $this->variableHolidays($year);
 
         return array_merge($fixedHolidays, $variableHolidays);
     }
 
-    protected function ensureYearCanBeCalculated(): void
+    protected function ensureYearCanBeCalculated(int $year): void
     {
-        if ($this->year < 1970) {
-            throw HolidaysException::yearTooLow($this->year);
+        if ($year < 1970) {
+            throw HolidaysException::yearTooLow($year);
         }
 
-        if ($this->year > 2037) {
-            throw HolidaysException::yearTooHigh($this->year);
+        if ($year > 2037) {
+            throw HolidaysException::yearTooHigh($year);
         }
     }
 
     /** @return array<string, CarbonImmutable> */
-    protected function fixedHolidays(): array
+    protected function fixedHolidays(int $year): array
     {
         $dates = [
             'Nieuwjaar' => '01-01',
@@ -46,16 +42,16 @@ protected function fixedHolidays(): array
         ];
 
         foreach ($dates as $name => $date) {
-            $dates[$name] = CarbonImmutable::createFromFormat('d-m-Y', "{$date}-{$this->year}");
+            $dates[$name] = CarbonImmutable::createFromFormat('d-m-Y', "{$date}-{$year}");
         }
 
         return $dates;
     }
 
     /** @return array<string, CarbonImmutable> */
-    protected function variableHolidays(): array
+    protected function variableHolidays(int $year): array
     {
-        $easter = CarbonImmutable::createFromTimestamp(easter_date($this->year))
+        $easter = CarbonImmutable::createFromTimestamp(easter_date($year))
             ->setTimezone('Europe/Brussels');
 
         return [

src/Enums/Country.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Spatie\Holidays\Enums;
+
+enum Country: string
+{
+    case Belgium = 'BE';
+}

src/Exceptions/HolidaysException.php

@@ -6,11 +6,6 @@
 
 class HolidaysException extends RuntimeException
 {
-    public static function unknownCountryCode(string $countryCode): self
-    {
-        return new self("Country code `{$countryCode}` is not supported");
-    }
-
     public static function noCountryCode(): self
     {
         return new self("Please provide a country code.");

src/Holidays.php

@@ -4,6 +4,7 @@
 
 use Carbon\CarbonImmutable;
 use Spatie\Holidays\Actions\Belgium;
+use Spatie\Holidays\Enums\Country;
 use Spatie\Holidays\Exceptions\HolidaysException;
 
 class Holidays
@@ -13,11 +14,14 @@ class Holidays
 
     protected int $year;
 
+    protected Country $country;
+
     private function __construct(
         ?int $year = null,
-        protected ?string $countryCode = 'BE' // @todo make this configurable ?
+        ?Country $country = null,
     ) {
         $this->year = $year ?? CarbonImmutable::now()->year;
+        $this->country = $country ?? Country::Belgium; // @todo make configurable ?
     }
 
     public static function new(): static
@@ -40,7 +44,7 @@ public function year(int $year): static
 
     public function country(string $countryCode): static
     {
-        return new static(countryCode: $countryCode);
+        return new static(country: Country::from($countryCode));
     }
 
     /** @return array<array{name: string, date: string}> */
@@ -55,10 +59,9 @@ public function get(): array
 
     protected function calculate(): self
     {
-        $action = match ($this->countryCode) {
-            'BE' => new Belgium(),
+        $action = match ($this->country) {
+            Country::Belgium => new Belgium(),
             null => throw HolidaysException::noCountryCode(),
-            default => throw HolidaysException::unknownCountryCode($this->countryCode),
         };
 
         $this->holidays = $action->execute($this->year);

tests/HolidaysTest.php

@@ -39,7 +39,7 @@
 
 it('cannot get all holidays of an unknown country code', function () {
     Holidays::new()->country('unknown')->get();
-})->throws(HolidaysException::class, 'Country code `unknown` is not supported');
+})->throws(ValueError::class, 'Country code `unknown` is not supported');
 
 it('cannot get holidays for years before 1970', function () {
     Holidays::new()->year(1969)->get();