add timezone normalizer

src/Serializer/Normalizer/DateTimeZoneNormalizer.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Serializer\Normalizer;
+
+use DateTimeZone;
+
+use function is_string;
+
+class DateTimeZoneNormalizer implements Normalizer
+{
+    public function normalize(mixed $value): ?string
+    {
+        if ($value === null) {
+            return null;
+        }
+
+        if (!$value instanceof DateTimeZone) {
+            throw new InvalidArgument();
+        }
+
+        return $value->getName();
+    }
+
+    public function denormalize(mixed $value): ?DateTimeZone
+    {
+        if ($value === null) {
+            return null;
+        }
+
+        if (!is_string($value)) {
+            throw new InvalidArgument();
+        }
+
+        return new DateTimeZone($value);
+    }
+}

tests/Unit/Serializer/Normalizer/DateTimeZoneNormalizerTest.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Tests\Unit\Serializer\Normalizer;
+
+use DateTimeZone;
+use Patchlevel\EventSourcing\Serializer\Normalizer\DateTimeZoneNormalizer;
+use Patchlevel\EventSourcing\Serializer\Normalizer\InvalidArgument;
+use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
+
+class DateTimeZoneNormalizerTest extends TestCase
+{
+    use ProphecyTrait;
+
+    public function testNormalizeWithNull(): void
+    {
+        $normalizer = new DateTimeZoneNormalizer();
+        $this->assertEquals(null, $normalizer->normalize(null));
+    }
+
+    public function testDenormalizeWithNull(): void
+    {
+        $normalizer = new DateTimeZoneNormalizer();
+        $this->assertEquals(null, $normalizer->denormalize(null));
+    }
+
+    public function testNormalizeWithInvalidArgument(): void
+    {
+        $this->expectException(InvalidArgument::class);
+
+        $normalizer = new DateTimeZoneNormalizer();
+        $normalizer->normalize(123);
+    }
+
+    public function testDenormalizeWithInvalidArgument(): void
+    {
+        $this->expectException(InvalidArgument::class);
+
+        $normalizer = new DateTimeZoneNormalizer();
+        $normalizer->denormalize(123);
+    }
+
+    public function testNormalizeWithValue(): void
+    {
+        $normalizer = new DateTimeZoneNormalizer();
+        $this->assertEquals('EDT', $normalizer->normalize(new DateTimeZone('EDT')));
+    }
+
+    public function testDenormalizeWithValue(): void
+    {
+        $normalizer = new DateTimeZoneNormalizer();
+        $this->assertEquals(new DateTimeZone('EDT'), $normalizer->denormalize('EDT'));
+    }
+}