Add holidays for Luxembourg (#165)

src/Countries/Luxembourg.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Spatie\Holidays\Countries;
+
+use Carbon\CarbonImmutable;
+
+class Luxembourg extends Country
+{
+    public function countryCode(): string
+    {
+        return 'lu';
+    }
+
+    protected function allHolidays(int $year): array
+    {
+        return array_merge([
+            'Neijoerschdag' => '01-01',
+            'Dag vun der Aarbecht' => '05-01',
+            'Europadag' => '05-09',
+            'Nationalfeierdag' => '06-23',
+            'Mariä Himmelfahrt' => '08-15',
+            'Allerhellgen' => '11-01',
+            'Chrëschtdag' => '12-25',
+            'Stiefesdag' => '12-26',
+        ], $this->variableHolidays($year));
+    }
+
+    /** @return array<string, CarbonImmutable> */
+    protected function variableHolidays(int $year): array
+    {
+        $easter = $this->easter($year);
+
+        return [
+            'Ouschterméindeg' => $easter->addDay(),
+            'Christi Himmelfahrt' => $easter->addDays(39),
+            'Péngschtméindeg' => $easter->addDays(50),
+        ];
+    }
+}

tests/.pest/snapshots/Countries/LuxembourgTest/it_can_calculate_luxembourgish_holidays.snap

@@ -0,0 +1,46 @@
+[
+    {
+        "name": "Neijoerschdag",
+        "date": "2024-01-01"
+    },
+    {
+        "name": "Ouschterm\u00e9indeg",
+        "date": "2024-04-01"
+    },
+    {
+        "name": "Dag vun der Aarbecht",
+        "date": "2024-05-01"
+    },
+    {
+        "name": "Europadag",
+        "date": "2024-05-09"
+    },
+    {
+        "name": "Christi Himmelfahrt",
+        "date": "2024-05-09"
+    },
+    {
+        "name": "P\u00e9ngschtm\u00e9indeg",
+        "date": "2024-05-20"
+    },
+    {
+        "name": "Nationalfeierdag",
+        "date": "2024-06-23"
+    },
+    {
+        "name": "Mari\u00e4 Himmelfahrt",
+        "date": "2024-08-15"
+    },
+    {
+        "name": "Allerhellgen",
+        "date": "2024-11-01"
+    },
+    {
+        "name": "Chr\u00ebschtdag",
+        "date": "2024-12-25"
+    },
+    {
+        "name": "Stiefesdag",
+        "date": "2024-12-26"
+    }
+]

tests/Countries/LuxembourgTest.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Spatie\Holidays\Tests\Countries;
+
+use Carbon\CarbonImmutable;
+use Spatie\Holidays\Holidays;
+
+it('can calculate luxembourgish holidays', function () {
+    CarbonImmutable::setTestNowAndTimezone('2024-01-01');
+
+    $holidays = Holidays::for(country: 'lu')->get();
+
+    expect($holidays)
+        ->toBeArray()
+        ->not()->toBeEmpty();
+
+    expect(formatDates($holidays))->toMatchSnapshot();
+});