Add US Holidays (#26)

src/Countries/UnitedStates.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Spatie\Holidays\Countries;
+
+use Carbon\CarbonImmutable;
+
+class UnitedStates extends Country
+{
+    public function countryCode(): string
+    {
+        return 'us';
+    }
+
+    protected function allHolidays(int $year): array
+    {
+        $holidays = array_merge([
+            'New Year\'s Day' => '01-01',
+            'Independence Day' => '07-04',
+            'Veterans Day' => '11-11',
+            'Christmas' => '12-25',
+        ], $this->variableHolidays($year));
+
+        if ($year >= 2021) {
+            $holidays['Juneteenth National Independence Day'] = '06-19';
+        }
+
+        return $holidays;
+    }
+
+    /** @return array<string, CarbonImmutable> */
+    protected function variableHolidays(int $year): array
+    {
+        $martinLutherKingDay = new CarbonImmutable("third monday of January $year", 'America/Los_Angeles');
+        $presidentsDay = new CarbonImmutable("third monday of February $year", 'America/Los_Angeles');
+        $memorialDay = new CarbonImmutable("last monday of May $year", 'America/Los_Angeles');
+        $laborDay = new CarbonImmutable("first monday of September $year", 'America/Los_Angeles');
+        $columbusDay = new CarbonImmutable("second monday of October $year", 'America/Los_Angeles');
+        $thanksgiving = new CarbonImmutable("fourth thursday of November $year", 'America/Los_Angeles');
+
+        return [
+            'Martin Luther King Day' => $martinLutherKingDay,
+            'Presidents\' Day' => $presidentsDay,
+            'Memorial Day' => $memorialDay,
+            'Labor Day' => $laborDay,
+            'Columbus Day' => $columbusDay,
+            'Thanksgiving' => $thanksgiving,
+        ];
+    }
+}

tests/.pest/snapshots/Countries/UnitedStatesTest/it_can_calculate_united_states_holidays_after_2021.snap

@@ -0,0 +1,46 @@
+[
+    {
+        "name": "New Year's Day",
+        "date": "2024-01-01"
+    },
+    {
+        "name": "Martin Luther King Day",
+        "date": "2024-01-15"
+    },
+    {
+        "name": "Presidents' Day",
+        "date": "2024-02-19"
+    },
+    {
+        "name": "Memorial Day",
+        "date": "2024-05-27"
+    },
+    {
+        "name": "Juneteenth National Independence Day",
+        "date": "2024-06-19"
+    },
+    {
+        "name": "Independence Day",
+        "date": "2024-07-04"
+    },
+    {
+        "name": "Labor Day",
+        "date": "2024-09-02"
+    },
+    {
+        "name": "Columbus Day",
+        "date": "2024-10-14"
+    },
+    {
+        "name": "Veterans Day",
+        "date": "2024-11-11"
+    },
+    {
+        "name": "Thanksgiving",
+        "date": "2024-11-28"
+    },
+    {
+        "name": "Christmas",
+        "date": "2024-12-25"
+    }
+]

tests/.pest/snapshots/Countries/UnitedStatesTest/it_can_calculate_united_states_holidays_before_2021.snap

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+[
+    {
+        "name": "New Year's Day",
+        "date": "2020-01-01"
+    },
+    {
+        "name": "Martin Luther King Day",
+        "date": "2020-01-20"
+    },
+    {
+        "name": "Presidents' Day",
+        "date": "2020-02-17"
+    },
+    {
+        "name": "Memorial Day",
+        "date": "2020-05-25"
+    },
+    {
+        "name": "Independence Day",
+        "date": "2020-07-04"
+    },
+    {
+        "name": "Labor Day",
+        "date": "2020-09-07"
+    },
+    {
+        "name": "Columbus Day",
+        "date": "2020-10-12"
+    },
+    {
+        "name": "Veterans Day",
+        "date": "2020-11-11"
+    },
+    {
+        "name": "Thanksgiving",
+        "date": "2020-11-26"
+    },
+    {
+        "name": "Christmas",
+        "date": "2020-12-25"
+    }
+]

tests/Countries/UnitedStatesTest.php

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+<?php
+
+namespace Spatie\Holidays\Tests\Countries;
+
+use Carbon\CarbonImmutable;
+use Spatie\Holidays\Holidays;
+
+it('can calculate united states holidays after 2021', function () {
+    CarbonImmutable::setTestNowAndTimezone('2024-01-01');
+
+    $holidays = Holidays::for(country: 'us')->get();
+
+    expect($holidays)
+        ->toBeArray()
+        ->not()->toBeEmpty();
+
+    expect(formatDates($holidays))->toMatchSnapshot();
+
+});
+
+it('can calculate united states holidays before 2021', function () {
+    CarbonImmutable::setTestNowAndTimezone('2020-01-01');
+
+    $holidays = Holidays::for(country: 'us')->get();
+
+    expect($holidays)
+        ->toBeArray()
+        ->not()->toBeEmpty();
+
+    expect(formatDates($holidays))->toMatchSnapshot();
+
+});