feat: add multiple working day determiner

app/Services/WorkingDays/Utils/MultipleWorkingDayDeterminer.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\WorkingDays\Utils;
+
+use App\Services\WorkingDays\WorkingDayDeterminerInterface;
+
+/**
+ * Determines if a given date is a working day -- on multiple working day determiners.
+ */
+class MultipleWorkingDayDeterminer implements WorkingDayDeterminerInterface
+{
+    /**
+     * @param array<int, WorkingDayDeterminerInterface> $workingDayDeterminers
+     */
+    public function __construct(
+        protected readonly array $workingDayDeterminers,
+    ) {
+    }
+
+    public function isWorkingDay(\DateTimeImmutable $date): bool
+    {
+        foreach ($this->workingDayDeterminers as $workingDayDeterminer) {
+            if (!$workingDayDeterminer->isWorkingDay($date)) {
+                return false;
+            }
+        }
+        return true; // All working day determiners returned true, so the date is a working day.
+    }
+
+    public function getWorkingDaysCount(\DateTimeImmutable $startDate, int $workingDays): int
+    {
+        $workingDaysCount = $workingDays;
+
+        foreach ($this->workingDayDeterminers as $workingDayDeterminer) {
+            $workingDaysCount = min($workingDaysCount, $workingDayDeterminer->getWorkingDaysCount($startDate, $workingDays));
+        }
+
+        return $workingDaysCount;
+    }
+}

tests/Unit/Services/WorkingDays/Utils/MultipleWorkingDayDeterminerTest.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Unit\Services\WorkingDays\Utils;
+
+use App\Services\WorkingDays\Utils\MultipleWorkingDayDeterminer;
+use App\Services\WorkingDays\WorkingDayDeterminerInterface;
+use PHPUnit\Framework\TestCase;
+
+class MultipleWorkingDayDeterminerTest extends TestCase
+{
+    public function testAllDeterminersReturnTrueForWorkingDay(): void
+    {
+        $date = new \DateTimeImmutable('2021-01-01');
+        $mock = $this->createMock(WorkingDayDeterminerInterface::class);
+        $mock->expects($this->once())->method('isWorkingDay')->with($date)->willReturn(true);
+        $mock1 = $this->createMock(WorkingDayDeterminerInterface::class);
+        $mock1->expects($this->once())->method('isWorkingDay')->with($date)->willReturn(true);
+        $determiner = new MultipleWorkingDayDeterminer([
+            $mock,
+            $mock1,
+        ]);
+
+        $this->assertTrue($determiner->isWorkingDay($date));
+    }
+
+    public function testFirstDeterminerReturnsFalseForWorkingDay(): void
+    {
+        $date = new \DateTimeImmutable('2021-01-01');
+        $mock = $this->createMock(WorkingDayDeterminerInterface::class);
+        $mock->expects($this->once())->method('isWorkingDay')->with($date)->willReturn(false);
+        $mock1 = $this->createMock(WorkingDayDeterminerInterface::class);
+        $mock1->expects($this->never())->method('isWorkingDay');
+        $determiner = new MultipleWorkingDayDeterminer([
+            $mock,
+            $mock1,
+        ]);
+
+        $this->assertFalse($determiner->isWorkingDay($date));
+    }
+}