Adds a test for the signing client decorator (#252)

Signed-off-by: Kim Pepper <[email protected]>

CHANGELOG.md

@@ -9,6 +9,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Added samples ([#218](https://github.com/opensearch-project/opensearch-php/pull/218))
 - Added support for PHP 8.3 and 8.4 ([#229](https://github.com/opensearch-project/opensearch-php/pull/229))
 - Added a Docker Compose config file for local development.
+- Added a test for the AWS signing client decorator
 ### Changed
 - Switched to PSR Interfaces
 - Increased PHP min version to 8.1

tests/Aws/SigningClientDecoratorTest.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenSearch\Tests\Aws;
+
+use Aws\Credentials\CredentialsInterface;
+use Aws\Signature\SignatureV4;
+use GuzzleHttp\Psr7\Request;
+use OpenSearch\Aws\SigningClientDecorator;
+use PHPUnit\Framework\TestCase;
+use Psr\Http\Client\ClientInterface;
+use Psr\Http\Message\ResponseInterface;
+
+/**
+ * Tests the signing client decorator.
+ *
+ * @coversDefaultClass \OpenSearch\Aws\SigningClientDecorator
+ */
+class SigningClientDecoratorTest extends TestCase
+{
+
+    /**
+     * Test that the decorator signs the request.
+     *
+     * @covers ::sendRequest
+     */
+    public function testSendRequest()
+    {
+        $client = $this->createMock(ClientInterface::class);
+        $credentials = $this->createMock(CredentialsInterface::class);
+        $signer = new SignatureV4('es', 'us-east-1');
+
+        $client->expects($this->once())
+            ->method('sendRequest')
+            ->with(
+                $this->callback(function (Request $req): bool {
+                    $this->assertEquals('localhost:9200', $req->getHeaderLine('Host'));
+                    $this->assertEquals('GET', $req->getMethod());
+                    $this->assertTrue($req->hasHeader('Authorization'));
+                    $this->assertTrue($req->hasHeader('x-amz-content-sha256'));
+                    $this->assertTrue($req->hasHeader('x-amz-date'));
+                    return true;
+                })
+            )
+            ->willReturn($this->createMock(ResponseInterface::class));
+
+
+        $decorator = new SigningClientDecorator($client, $credentials, $signer);
+        $request = new Request('GET', 'http://localhost:9200/_search');
+        $decorator->sendRequest($request);
+    }
+}