Add trait MockGuzzleClient for tests

tests/Concerns/MockGuzzleClient.php

@@ -0,0 +1,64 @@
+<?php
+
+use GuzzleHttp\Client;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\Psr7\Response;
+use GuzzleHttp\Handler\MockHandler;
+use GuzzleHttp\Exception\RequestException;
+
+/**
+ * @see http://docs.guzzlephp.org/en/stable/testing.html
+ * @see https://christrombley.me/blog/testing-guzzle-6-responses-with-laravel
+ */
+trait MockGuzzleClient
+{
+    public $guzzleMockHandler;
+
+    /**
+     * Set up for mocking Guzzle HTTP client.
+     *
+     * @param Response|RequestException $responses
+     * @return void
+     */
+    public function setupGuzzleClientMock($responses = null)
+    {
+        $this->guzzleMockHandler = new MockHandler($responses);
+        $handler = HandlerStack::create($this->guzzleMockHandler);
+        $client = new Client(['handler' => $handler]);
+
+        // Inject to Laravel service container
+        $this->app->instance(Client::class, $client);
+    }
+
+    /**
+     * Add responses to Guzzle client's mock queue.
+     * Pass a Response or RequestException instance, or an array of them.
+     *
+     * @param array|Response|RequestException|integer $response
+     * @param array       $headers
+     * @param string      $body
+     * @param string      $version
+     * @param string|null $reason
+     * @return void
+     */
+    public function appendToGuzzleQueue($response = 200, $headers = [], $body = '', $version = '1.1', $reason = null)
+    {
+        if (! $this->guzzleMockHandler) {
+            $this->setupGuzzleClientMock();
+        }
+
+        if (is_array($response)) {
+            foreach ($response as $single) {
+                $this->appendToGuzzleQueue($single);
+            }
+            return;
+        }
+
+        if ($response instanceof Response || $response instanceof RequestException) {
+            return $this->guzzleMockHandler->append($response);
+        }
+
+        return $this->guzzleMockHandler->append(new Response($response, $headers, $body, $version, $reason));
+    }
+}

tests/TestCase.php

@@ -2,6 +2,7 @@
 
 class TestCase extends Illuminate\Foundation\Testing\TestCase
 {
+    use MockGuzzleClient;
     use InteractsWithCache;
 
     /**