feature #35893 [HttpClient][DI] Add an option to use the MockClient in functional tests (GaryPEGEOT)

This PR was squashed before being merged into the 5.2-dev branch.

Discussion
----------

[HttpClient][DI] Add an option to use the MockClient in functional tests

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       |
| License       | MIT
| Doc PR        | TODO

Let's say you want to mock HTTP responses in your test or dev environment:

First, you create an invokable class responsible of generating the response:
```php
namespace App\Tests;

use Symfony\Contracts\HttpClient\ResponseInterface;

class MyAwesomeCallback
{
    public function __invoke(string $method, string $url, array $options = []): ResponseInterface
    {
        // load a fixture file or generate dynamic data
    }
}
```

Then configure it:
```yaml

# config/services_test.yaml
services:
   # ...
   App\Tests\MyAwesomeCallback: ~

# config/packages/test/framework.yaml
framework:
    http_client:
        mock_response_factory: App\Tests\MyAwesomeCallback
```

The HttpClient will now be using MockHttpClient in your functional test:
```php
$client = static::createClient();

// No live HTTP connection made
$client->request('GET', '/path-with-http-call');
```

Commits
-------

b53739c79d [HttpClient][DI] Add an option to use the MockClient in functional tests

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php

@@ -1450,6 +1450,9 @@ class Configuration implements ConfigurationInterface
                                 ->end()
                             ->end()
                         ->end()
+                        ->scalarNode('mock_response_factory')
+                            ->info('The id of the service that should generate mock responses. It should be either an invokable or an iterable.')
+                        ->end()
                         ->arrayNode('scoped_clients')
                             ->useAttributeAsKey('name')
                             ->normalizeKeys(false)

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -63,6 +63,7 @@ use Symfony\Component\Form\ChoiceList\Factory\CachingFactoryDecorator;
 use Symfony\Component\Form\FormTypeExtensionInterface;
 use Symfony\Component\Form\FormTypeGuesserInterface;
 use Symfony\Component\Form\FormTypeInterface;
+use Symfony\Component\HttpClient\MockHttpClient;
 use Symfony\Component\HttpClient\ScopingHttpClient;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\CacheClearer\CacheClearerInterface;
@@ -2010,6 +2011,12 @@ class FrameworkExtension extends Extension
                 $container->registerAliasForArgument('psr18.'.$name, ClientInterface::class, $name);
             }
         }
+
+        if ($responseFactoryId = $config['mock_response_factory'] ?? null) {
+            $container->getDefinition($httpClientId)
+                ->setClass(MockHttpClient::class)
+                ->setArguments([new Reference($responseFactoryId)]);
+        }
     }
 
     private function registerMailerConfiguration(array $config, ContainerBuilder $container, PhpFileLoader $loader)

src/Symfony/Bundle/FrameworkBundle/Resources/config/schema/symfony-1.0.xsd

@@ -510,6 +510,7 @@
         </xsd:sequence>
         <xsd:attribute name="enabled" type="xsd:boolean" />
         <xsd:attribute name="max-host-connections" type="xsd:integer" />
+        <xsd:attribute name="mock-response-factory" type="xsd:string" />
     </xsd:complexType>
 
     <xsd:complexType name="http_client_default_options" mixed="true">

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/php/http_client_mock_response_factory.php

@@ -0,0 +1,8 @@
+<?php
+
+$container->loadFromExtension('framework', [
+    'http_client' => [
+        'default_options' => null,
+        'mock_response_factory' => 'my_response_factory',
+    ],
+]);

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/xml/http_client_mock_response_factory.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:framework="http://symfony.com/schema/dic/symfony"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd
+        http://symfony.com/schema/dic/symfony http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
+
+    <framework:config>
+        <framework:http-client mock-response-factory="my_response_factory">
+            <framework:default-options />
+        </framework:http-client>
+    </framework:config>
+</container>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/yml/http_client_mock_response_factory.yml

@@ -0,0 +1,4 @@
+framework:
+    http_client:
+        default_options: ~
+        mock_response_factory: my_response_factory

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php

@@ -41,6 +41,7 @@ use Symfony\Component\DependencyInjection\ParameterBag\EnvPlaceholderParameterBa
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\Form\Serializer\FormErrorNormalizer;
+use Symfony\Component\HttpClient\MockHttpClient;
 use Symfony\Component\HttpClient\ScopingHttpClient;
 use Symfony\Component\HttpKernel\DependencyInjection\LoggerPass;
 use Symfony\Component\Messenger\Transport\TransportFactory;
@@ -1567,6 +1568,21 @@ abstract class FrameworkExtensionTest extends TestCase
         $this->assertEquals(new Reference('app.another_bus'), $container->getDefinition('mailer.mailer')->getArgument(1));
     }
 
+    public function testHttpClientMockResponseFactory()
+    {
+        $container = $this->createContainerFromFile('http_client_mock_response_factory');
+
+        $definition = $container->getDefinition('http_client');
+
+        $this->assertSame(MockHttpClient::class, $definition->getClass());
+        $this->assertCount(1, $definition->getArguments());
+
+        $argument = $definition->getArgument(0);
+
+        $this->assertInstanceOf(Reference::class, $argument);
+        $this->assertSame('my_response_factory', (string) $argument);
+    }
+
     protected function createContainer(array $data = [])
     {
         return new ContainerBuilder(new EnvPlaceholderParameterBag(array_merge([