Use flex client wrapper for profiling if needed

Collector/ProfileClient.php

@@ -47,23 +47,18 @@ class ProfileClient implements HttpClient, HttpAsyncClient
     private $eventNames = [];
 
     /**
-     * @param HttpClient|HttpAsyncClient $client    The client to profile. Client must implement both HttpClient and
-     *                                              HttpAsyncClient interfaces.
+     * @param HttpClient|HttpAsyncClient $client    The client to profile. Client must implement HttpClient or
+     *                                              HttpAsyncClient interface.
      * @param Collector                  $collector
      * @param Formatter                  $formatter
      * @param Stopwatch                  $stopwatch
      */
     public function __construct($client, Collector $collector, Formatter $formatter, Stopwatch $stopwatch)
     {
         if (!($client instanceof HttpClient && $client instanceof HttpAsyncClient)) {
-            throw new \RuntimeException(sprintf(
-                '%s first argument must implement %s and %s. Consider using %s.',
-                    __METHOD__,
-                    HttpClient::class,
-                    HttpAsyncClient::class,
-                    FlexibleHttpClient::class
-            ));
+            $client = new FlexibleHttpClient($client);
         }
+
         $this->client = $client;
         $this->collector = $collector;
         $this->formatter = $formatter;

Tests/Functional/Issue206.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Http\HttplugBundle\Tests\Functional;
+
+use Http\Client\Common\HttpMethodsClient;
+use Http\Client\Common\PluginClient;
+use Http\Client\Common\PluginClientFactory;
+use Http\Discovery\HttpClientDiscovery;
+use Http\Discovery\MessageFactoryDiscovery;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+
+class Issue206 extends WebTestCase
+{
+    public function testCustomClientDoesNotCauseException()
+    {
+        static::bootKernel();
+        $container = static::$kernel->getContainer();
+        PluginClientFactory::setFactory([$container->get('Http\Client\Common\PluginClientFactory'), 'createClient']);
+
+        // Create a client
+        $myCustomClient = new HttpMethodsClient(HttpClientDiscovery::find(), MessageFactoryDiscovery::find());
+        $pluginClient = (new PluginClientFactory())->createClient($myCustomClient, []);
+
+        // If we get to this line, no exceptions has been thrown.
+        $this->assertInstanceOf(PluginClient::class, $pluginClient);
+    }
+}