Add "Mock responses in functional tests" part (#220)

Author: GaryPEGEOT

clients/mock-client.rst

@@ -140,4 +140,9 @@ Or set a default exception::
         }
     }
 
+
+.. hint::
+
+    If you're using the :doc:`/integrations/symfony-bundle`, the mock client is available as a service with ``httplug.client.mock`` id.
+
 .. include:: includes/further-reading-async.inc

integrations/symfony-bundle.rst

@@ -205,6 +205,7 @@ services are:
 * ``httplug.factory.guzzle6``
 * ``httplug.factory.react``
 * ``httplug.factory.socket``
+* ``httplug.factory.mock`` (Install ``php-http/mock-client`` first)
 
 Plugins
 ```````
@@ -342,6 +343,34 @@ The only steps they need is ``require`` one of the adapter implementations in
 their projects ``composer.json`` and instantiating the ``HttplugBundle`` in
 their kernel.
 
+Mock Responses In Functional Tests
+``````````````````````````````````
+
+First thing to do is add the :doc:`php-http/mock-client </clients/mock-client>` to your ``require-dev`` section.
+Then, use the mock client factory in your test environment configuration:
+
+.. code-block:: yaml
+
+    # config_test.yml
+    httplug:
+        clients:
+            my_awesome_client:
+                factory: 'httplug.factory.mock' # replace factory
+
+To mock a response in your tests, do:
+
+.. code-block:: php
+
+    // SomeWebTestCase.php
+    $client = static::createClient();
+
+    // If your test has the client (BrowserKit) make multiple requests, you need to disable reboot as the kernel is rebooted on each request.
+    // $client->disableReboot();
+    
+    $response = $this->createMock('Psr\Http\Message\ResponseInterface');
+    $response->method('getBody')->willReturn(/* Psr\Http\Message\Interface instance containing expected response content. */);
+    $client->getContainer()->get('httplug.client.mock')->addResponse($response);
+
 .. |clearfloat|  raw:: html
 
     <div style="clear:left"></div>