Add mock client factory for test purpose.

[GaryPEGEOT]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no
Related tickets	fixes partially #212
Documentation	php-http/documentation#220
License	MIT

What's in this PR?

Add a mock client factory to ease functional testing.

Example Usage

Configuration:

    # config_test.yml
    httplug:
        clients:
            my_awesome_client:
                factory: 'httplug.factory.mock' # replace factory

Usage:

$client = static::createClient();
// $client->disableReboot(); You might uncomment this if your client (BrowserKit) make multiple requests as kernel is rebooted on each request.

$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);

[dbu]

great idea, thanks!

you could add the mock client to the composer.json suggest section and propose to add it in require-dev of the users project.

[dbu]

please use the ::class pseudoconstant. we are on php 5.5 or newer.

[dbu]

lets use the ::class pseudoconstant here. and make the use statement say use Http\Mock\Client as MockClient; to make things more readable.

[dbu]

this will create a new client on each call, if none has been registered. should we instead register the newly created client if none was set?

[dbu]

i think this service should be removed from the container when the mock client is not available. that way, users notice problems at container build time instead of at runtime.

[dbu]

thanks, looks good to me!

[fbourigault]

Great! I wrote a comment to improve the readability.

[fbourigault]

Instead of removing a definition when the class does not exist, could you move the relevant service definition to a dedicated file and load this file if the class is available?

[dbu]

looks good to me, thanks!