ENGCOM-5350: USPS Client Mock #753

 - Merge Pull Request magento/graphql-ce#753 from pmclain/graphql-ce:issue/739
 - Merged commits:
   1. 2c363e3
   2. a5ccfc5

Author: magento-engcom-team

dev/tests/api-functional/_files/Magento/TestModuleUsps/Model/MockAsyncClient.php

@@ -0,0 +1,62 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\TestModuleUsps\Model;
+
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\HTTP\AsyncClient\HttpResponseDeferredInterface;
+use Magento\Framework\HTTP\AsyncClient\Request;
+use Magento\Framework\HTTP\AsyncClient\ResponseFactory;
+use Magento\Framework\HTTP\AsyncClientInterface;
+
+/**
+ * Mock async client returns USPS rate responses
+ */
+class MockAsyncClient implements AsyncClientInterface
+{
+    /**
+     * @var MockResponseBodyLoader
+     */
+    private $mockResponseBodyLoader;
+
+    /**
+     * @var ResponseFactory
+     */
+    private $responseFactory;
+
+    /**
+     * @param MockResponseBodyLoader $mockResponseBodyLoader
+     * @param ResponseFactory $responseFactory
+     */
+    public function __construct(
+        MockResponseBodyLoader $mockResponseBodyLoader,
+        ResponseFactory $responseFactory
+    ) {
+        $this->mockResponseBodyLoader = $mockResponseBodyLoader;
+        $this->responseFactory = $responseFactory;
+    }
+
+    /**
+     * Fetch mock USPS rate response
+     *
+     * @param Request $request
+     * @return HttpResponseDeferredInterface
+     * @throws LocalizedException
+     */
+    public function request(Request $request): HttpResponseDeferredInterface
+    {
+        return new MockDeferredResponse(
+            $this->responseFactory->create(
+                [
+                    'statusCode' => 200,
+                    'headers' => [],
+                    'body' => $this->mockResponseBodyLoader->loadForRequest($request),
+                ]
+            )
+        );
+    }
+}

dev/tests/api-functional/_files/Magento/TestModuleUsps/Model/MockDeferredResponse.php

@@ -0,0 +1,64 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\TestModuleUsps\Model;
+
+use Magento\Framework\Async\CancelingDeferredException;
+use Magento\Framework\HTTP\AsyncClient\HttpResponseDeferredInterface;
+use Magento\Framework\HTTP\AsyncClient\Response;
+
+/**
+ * Mock for HTTP responses.
+ */
+class MockDeferredResponse implements HttpResponseDeferredInterface
+{
+    /**
+     * @var Response
+     */
+    private $response;
+
+    /**
+     * MockDeferredResponse constructor.
+     * @param Response $response
+     */
+    public function __construct(Response $response)
+    {
+        $this->response = $response;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function cancel(bool $force = false): void
+    {
+        throw new CancelingDeferredException('Cannot be canceled');
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function isCancelled(): bool
+    {
+        return false;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function isDone(): bool
+    {
+        return true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function get(): Response
+    {
+        return $this->response;
+    }
+}

dev/tests/api-functional/_files/Magento/TestModuleUsps/Model/MockResponseBodyLoader.php

@@ -0,0 +1,68 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\TestModuleUsps\Model;
+
+use Magento\Framework\Exception\NotFoundException;
+use Magento\Framework\HTTP\AsyncClient\Request;
+use Magento\Framework\Module\Dir;
+use Magento\Framework\Filesystem\Io\File;
+
+/**
+ * Load mock response body for USPS rate request
+ */
+class MockResponseBodyLoader
+{
+    private const RESPONSE_FILE_PATTERN = '%s/_files/mock_response_%s.xml';
+
+    /**
+     * @var Dir
+     */
+    private $moduleDirectory;
+
+    /**
+     * @var File
+     */
+    private $fileIo;
+
+    /**
+     * @param Dir $moduleDirectory
+     * @param File $fileIo
+     */
+    public function __construct(
+        Dir $moduleDirectory,
+        File $fileIo
+    ) {
+        $this->moduleDirectory = $moduleDirectory;
+        $this->fileIo = $fileIo;
+    }
+
+    /**
+     * Loads mock response xml for a given request
+     *
+     * @param Request $request
+     * @return string
+     * @throws NotFoundException
+     */
+    public function loadForRequest(Request $request): string
+    {
+        $moduleDir = $this->moduleDirectory->getDir('Magento_TestModuleUsps');
+
+        $destination = 'us';
+        if (strpos($request->getUrl(), 'IntlRateV2Request') !== false) {
+            $destination = 'ca';
+        }
+
+        $responsePath = sprintf(static::RESPONSE_FILE_PATTERN, $moduleDir, $destination);
+
+        if (!$this->fileIo->fileExists($responsePath)) {
+            throw new NotFoundException(__('%1 is not a valid destination country.', $destination));
+        }
+
+        return $this->fileIo->read($responsePath);
+    }
+}