MAGE-986 Add discrete serializer wrapper service with unit tests

Author: cammonro

Service/Serializer.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Algolia\AlgoliaSearch\Service;
+
+use Magento\Framework\Serialize\SerializerInterface;
+
+/**
+ * Used for handling configuration data, this serializer service provides a wrapper around the Magento framework serializer.
+ */
+class Serializer
+{
+    public function __construct(
+        protected SerializerInterface $serializer
+    ) {}
+
+    /**
+     * \Magento\Framework\Serialize\SerializerInterface should never return a string
+     * but the return type is flagged as either `bool|string`
+     * This safely ensures the proper string type is always returned no matter what
+     *
+     * @param array $value
+     * @return string
+     */
+    public function serialize(array $value): string
+    {
+        $result = $this->serializer->serialize($value);
+        return is_string($result) ? $result : '';
+    }
+
+    /**
+     * This deserializes the argument by first attempting to perform a quick JSON decode
+     * before falling back to the Magento framework serializer object
+     *
+     * Note that if the argument value is falsey then it will return false
+     * (This is legacy behavior)
+     *
+     * @param $value
+     * @return mixed Returns false if argument supplied is falsey - otherwise returns the deserialized object
+     */
+    public function unserialize($value): mixed
+    {
+        if (in_array($value, [false, null, ''], true)) {
+            return false;
+        }
+
+        $unserialized = json_decode($value, true);
+        if (json_last_error() === JSON_ERROR_NONE) {
+            return $unserialized;
+        }
+        return $this->serializer->unserialize($value);
+    }
+}

Test/Unit/Service/SerializerTest.php

@@ -0,0 +1,89 @@
+<?php
+
+namespace Algolia\AlgoliaSearch\Test\Unit\Service;
+
+use Algolia\AlgoliaSearch\Service\Serializer;
+use Magento\Framework\Serialize\SerializerInterface;
+use PHPUnit\Framework\TestCase;
+
+class SerializerTest extends TestCase
+{
+    private ?SerializerInterface $serializerMock = null;
+    protected ?Serializer $serializer = null;
+
+    protected function setUp(): void
+    {
+        $this->serializerMock = $this->createMock(SerializerInterface::class);
+
+        $this->serializer = new Serializer($this->serializerMock);
+    }
+
+    /**
+     * Add data provider?
+     * @return void
+     */
+    public function testSerializeReturnsString(): void
+    {
+        $unserialized = ['foo' => 'bar'];
+        $this->serializerMock
+            ->expects($this->once())
+            ->method('serialize')
+            ->with($unserialized)
+            ->willReturn('{"foo":"bar"}');
+        $result = $this->serializer->serialize($unserialized);
+        $this->assertEquals('{"foo":"bar"}', $result);
+    }
+
+    public function testSerializeFailure(): void
+    {
+        $unserialized = [];
+        $this->serializerMock
+            ->expects($this->once())
+            ->method('serialize')
+            ->with($unserialized)
+            ->willReturn(false);
+        $result = $this->serializer->serialize($unserialized);
+        $this->assertEquals('', $result);
+    }
+
+    public function testUnserializeReturnsFalseOnEmptyValues(): void
+    {
+        $this->assertFalse($this->serializer->unserialize(null));
+        $this->assertFalse($this->serializer->unserialize(false));
+        $this->assertFalse($this->serializer->unserialize(''));
+    }
+
+    public function testUnserializeHandlesValidJson(): void
+    {
+        $json = '{"key":"value"}';
+        $this->assertEquals(['key' => 'value'], $this->serializer->unserialize($json));
+    }
+
+    public function testUnserializeFallsBackToSerializer(): void
+    {
+        $serialized = 'a:1:{s:3:"foo";s:3:"bar";}'; // PHP serialized data
+
+        $this->serializerMock
+            ->expects($this->once())
+            ->method('unserialize')
+            ->with($serialized)
+            ->willReturn(['foo' => 'bar']);
+
+        $this->assertEquals(['foo' => 'bar'], $this->serializer->unserialize($serialized));
+    }
+
+    public function testUnserializeFailsBothJsonAndSerializer(): void
+    {
+        $badData = 'not_serialized_at_all';
+
+        $this->serializerMock
+            ->expects($this->once())
+            ->method('unserialize')
+            ->with($badData)
+            ->willThrowException(new \InvalidArgumentException());
+
+        $this->expectException(\InvalidArgumentException::class);
+
+        $this->serializer->unserialize($badData);
+    }
+}