Mocking external library in PHP/Codeigniter - php

Question

Using the ci-php-unit-test library to do unit tests for PHP/codeigniter, and unit testing controller methods.
Having trouble working out how to mock an external library that is installed using composer.
my SUT method is:
function twitter()
{
$this->load->model('misc/twitter_model');
$request_token = [];
$request_token['oauth_token'] = $_SESSION['twitter_oauth_token'];
$request_token['oauth_token_secret'] = $_SESSION['twitter_oauth_token_secret'];
if ( (isset($_GET['oauth_token'])
&& ($request_token['oauth_token'] !== $_GET['oauth_token'])))
{
log_message('info','abort something is wrong!');
}
else
{
$connection = new Abraham\TwitterOAuth\TwitterOAuth(TWITTER_CONSUMER_KEY, TWITTER_CONSUMER_SECRET, $request_token['oauth_token'], $request_token['oauth_token_secret']);
$access_token = $connection->oauth("oauth/access_token", array("oauth_verifier" => $_REQUEST['oauth_verifier']));
$this->session->set_userdata('twitter_access_token',$access_token);
redirect(get_session('twitter_callback1'));
}
}
my test method (so far) is:
public function test_twitter()
{
$_SESSION['twitter_oauth_token'] = 'twitter_oauth_token';
$_SESSION['twitter_oauth_token_secret'] = 'twitter_oauth_token_secret';
$this->request->setCallable(
function (& $CI) {
// Get mock object
$twitter_oa = $this->getMockBuilder('TwitterOAuth')
->disableOriginalConstructor()
->setMethods(['oauth'])
->getMock();
$twitter_oa->method('oauth')
->willReturn('access_token');
}
);
$output = $this->request('GET','callbacks/twitter',['oauth_token'=>'twitter_oauth_token']);
var_export($output);
}
But the original library is being executed because it isn't being mocked - the $twitter_oa isn't being attached to the CI instance.
This is because the external library has not been instantiated after the codeigniter controller has been instantiated. (this is was the setCallable method does)
My question is, how can I mock TwitterOAuth after the codeigniter controller is instantiated so it can return set testing text?
(and obviously not instantiate the twitter Oauth library)

Answer 1

ok, so when you see a new Class(); in unit testing, you have to re-work something. This may not be the best option, but this works for me.
in the SUT, the controller code is now:
function twitter()
{
$this->load->model('misc/twitter_model');
$request_token = [];
$request_token['oauth_token'] = $_SESSION['twitter_oauth_token'];
$request_token['oauth_token_secret'] = $_SESSION['twitter_oauth_token_secret'];
if ( (isset($_GET['oauth_token'])
&& ($request_token['oauth_token'] !== $_GET['oauth_token'])))
{
log_message('info','abort something is wrong!');
}
else
{
$connection = $this->twitter_connection($request_token['oauth_token'],$request_token['oauth_token_secret']);
$access_token = $connection->oauth("oauth/access_token", array("oauth_verifier" => $_REQUEST['oauth_verifier']));
$this->session->set_userdata('twitter_access_token',$access_token);
redirect(get_session('twitter_callback1'));
}
}
/**
* #param $token
* #param $secret
* #return \Abraham\TwitterOAuth\TwitterOAuth
*
* #codeCoverageIgnore
*
*/
public function twitter_connection($token, $secret)
{
return new Abraham\TwitterOAuth\TwitterOAuth(
TWITTER_CONSUMER_KEY,
TWITTER_CONSUMER_SECRET,
$token,
$secret);
}
There is a new file in APPPATH.tests/mocks/external_libaries with:
class MockTwitterOAuth
{
public function oauth()
{
return 'access_token';
}
}
and the test code is now:
public function test_twitter()
{
$_SESSION['twitter_oauth_token'] = 'twitter_oauth_token';
$_SESSION['twitter_oauth_token_secret'] = 'twitter_oauth_token_secret';
$_SESSION['twitter_callback1'] = 'cb1';
require_once(APPPATH.'tests/mocks/external_libraries/MockTwitterOauth.php');
$twitter_connection = new MockTwitterOAuth();
MonkeyPatch::patchMethod('Callbacks',[
'twitter_connection'=>$twitter_connection
]);
$output = $this->request('GET','callbacks/twitter',['oauth_token'=>'twitter_oauth_token']);
$this->assertNull($output);
$this->assertResponseCode(HTTP_FOUND);
$this->assertRedirect(base_url('cb1'));
$this->assertEquals('access_token',$_SESSION['twitter_access_token']);
}
The trick is to have twitter connection return a new TwitterOAuth class normally, but when the system is unit testing, return the MockTwitterOAuth class that only has one method instead. This can be accomplished by monkeypatching the controller code.
Hope this answer is useful for others, and if you haven't used it already the https://github.com/kenjis/ci-phpunit-test is pretty good, even though it is hard to get started. Purchasing the companion book is recommended!