Add a safety catch for max restarts

spec/PluginClientSpec.php

@@ -4,11 +4,20 @@
 
 use Http\Client\HttpAsyncClient;
 use Http\Client\HttpClient;
+use Http\Client\Plugin\Plugin;
 use Http\Promise\Promise;
 use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;
 use PhpSpec\ObjectBehavior;
 
+class DefectuousPlugin implements Plugin
+{
+    public function handleRequest(RequestInterface $request, callable $next, callable $first)
+    {
+        return $first($request);
+    }
+}
+
 class PluginClientSpec extends ObjectBehavior
 {
     function let(HttpClient $client)
@@ -45,4 +54,11 @@ function it_sends_async_request_with_underlying_client(HttpAsyncClient $asyncCli
         $this->beConstructedWith($asyncClient);
         $this->sendAsyncRequest($request)->shouldReturn($promise);
     }
+
+    function it_throws_loop_exception(HttpClient $client, RequestInterface $request)
+    {
+        $this->beConstructedWith($client, [new DefectuousPlugin()]);
+
+        $this->shouldThrow('Http\Client\Plugin\Exception\LoopException')->duringSendRequest($request);
+    }
 }

src/Exception/LoopException.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Http\Client\Plugin\Exception;
+
+use Http\Client\Exception\RequestException;
+
+class LoopException extends RequestException
+{
+}

src/PluginClient.php

@@ -4,7 +4,9 @@
 
 use Http\Client\HttpAsyncClient;
 use Http\Client\HttpClient;
+use Http\Client\Plugin\Exception\LoopException;
 use Psr\Http\Message\RequestInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
 
 /**
  * The client managing plugins and providing a decorator around HTTP Clients.
@@ -27,13 +29,21 @@ class PluginClient implements HttpClient, HttpAsyncClient
      */
     protected $plugins;
 
+    /**
+     * A list of options.
+     *
+     * @var array
+     */
+    protected $options;
+
     /**
      * @param HttpClient|HttpAsyncClient $client
      * @param Plugin[]                   $plugins
+     * @param array                      $options
      *
      * @throws \RuntimeException if client is not an instance of HttpClient or HttpAsyncClient
      */
-    public function __construct($client, array $plugins = [])
+    public function __construct($client, array $plugins = [], array $options = [])
     {
         if ($client instanceof HttpAsyncClient) {
             $this->client = $client;
@@ -44,6 +54,7 @@ public function __construct($client, array $plugins = [])
         }
 
         $this->plugins = $plugins;
+        $this->options = $this->configure($options);
     }
 
     /**
@@ -66,6 +77,23 @@ public function sendAsyncRequest(RequestInterface $request)
         return $pluginChain($request);
     }
 
+    /**
+     * Configure the plugin client.
+     *
+     * @param array $options
+     *
+     * @return array
+     */
+    protected function configure(array $options = [])
+    {
+        $resolver = new OptionsResolver();
+        $resolver->setDefaults([
+            'max_restarts' => 10,
+        ]);
+
+        return $resolver->resolve($options);
+    }
+
     /**
      * @param Plugin[] $pluginList
      *
@@ -74,6 +102,8 @@ public function sendAsyncRequest(RequestInterface $request)
     private function createPluginChain($pluginList)
     {
         $client = $this->client;
+        $options = $this->options;
+
         $lastCallable = function (RequestInterface $request) use ($client) {
             return $client->sendAsyncRequest($request);
         };
@@ -87,6 +117,17 @@ private function createPluginChain($pluginList)
             $firstCallable = $lastCallable;
         }
 
+        $firstCalls = 0;
+        $firstCallable = function (RequestInterface $request) use ($options, $lastCallable, &$firstCalls) {
+            if ($firstCalls > $options['max_restarts']) {
+                throw new LoopException('Too many restarts in plugin client', $request);
+            }
+
+            ++$firstCalls;
+
+            return $lastCallable($request);
+        };
+
         return $firstCallable;
     }
 }