add class for Return-Path header

src/Header/ReturnPath.php

@@ -0,0 +1,39 @@
+<?php
+declare(strict_types=1);
+
+namespace Genkgo\Mail\Header;
+
+use Genkgo\Mail\EmailAddress;
+use Genkgo\Mail\HeaderInterface;
+
+final class ReturnPath implements HeaderInterface
+{
+    /**
+     * @var EmailAddress
+     */
+    private $reversePath;
+
+    /**
+     * @param EmailAddress $reversePath
+     */
+    public function __construct(EmailAddress $reversePath)
+    {
+        $this->reversePath = $reversePath;
+    }
+
+    /**
+     * @return HeaderName
+     */
+    public function getName(): HeaderName
+    {
+        return new HeaderName('Return-Path');
+    }
+
+    /**
+     * @return HeaderValue
+     */
+    public function getValue(): HeaderValue
+    {
+        return HeaderValue::fromEncodedString((string)$this->reversePath);
+    }
+}

test/Unit/Header/ReturnPathTest.php

@@ -0,0 +1,32 @@
+<?php
+declare(strict_types=1);
+
+namespace Genkgo\TestMail\Unit\Header;
+
+use Genkgo\Mail\Header\ReturnPath;
+use Genkgo\TestMail\AbstractTestCase;
+use Genkgo\Mail\EmailAddress;
+
+final class ReturnPathTest extends AbstractTestCase
+{
+    /**
+     * @test
+     * @dataProvider provideValues
+     */
+    public function it_produces_correct_values($recipientEmail, $headerName, $headerValue): void
+    {
+        $header = new ReturnPath(new EmailAddress($recipientEmail));
+        $this->assertEquals($headerName, (string)$header->getName());
+        $this->assertEquals($headerValue, (string)$header->getValue());
+    }
+
+    /**
+     * @return array
+     */
+    public function provideValues(): array
+    {
+        return [
+            ['[email protected]', 'Return-Path', '[email protected]'],
+        ];
+    }
+}