Mocking a method on dynamically allocated instance? - php

Background: I'm working on an MVC framework for some practice, and want to make sure everything is 100% unit tested.
The setup currently is to have an instance of the application class (Ex_App). The main script asks a Dispatcher/Router for a controller name. This controller name is the name of a class implementing Ex_Controller. The result is returned as an instance of Ex_Dispatch_Result. This result is passed to the Ex_App instance using an invokeController($dispatchResult) function.
And this is where magic happens. The listing below is an excerpt:
$controllerName = $dispatchResult->getControllerName();
... checks for validaty of class name ...
$controller = new $controllerName();
$controller->prepare($this);
I'm using PHPUnit to do my unit testing, and am able to mock the dispatch result, correctly check that validating the class name of the controller works. The problem is how to check if prepare is called.
I'd like to do something similar to:
$mockController = $this->getMockBuilder('Ex_Controller')
->setMockClassName('Invoke_Correct_Controller')
->getMock();
$mockController->expects($this->once())->method('prepare');
However since a new instance of Invoke_Correct_Controller is created upon calling invokeController, it will not be this mock and thus the expects() call is completely irrelevant.
I could make the Ex_Dispatch_Result class responsible for returning a controller and testing that, but before returning an instance I will need to verify the correctness of the class name and in my opinion that responsibility should be with the Ex_App class and not the "dumb shell" Ex_Dispatch_Result class.
Is there something I am missing in the PHPUnit framework that I could use to test the code here, or some useful pattern that could work in my instance? I feel passing around controller names scales way better than passing around instances of controllers from the start, requiring the initialization of every possible controller. So, I kinda want to stick to passing around names and using the Ex_App as a factory for the controller instance.
Maybe I'm just over-thinking part of this problem, but that happens sometimes. It's why a fresh look by a third party often works :-)

There are couple of things you could do:
Extract controller creation logic to separate class e.g. ControllerFactory, and then mock controller factory instance, so that it returns your $mockController.
Extract controller creation logic to separate method and use partial mocking.
Return $mockController from $dispatchResult->getControllerName(), which probably requires mocking of $dispatchResult or even something else.
If you want more detailed answer, please provide more code samples of your classes and methods.

Related

PHPUnit gives error: Target [Illuminate\Contracts\View\Factory] is not instantiable

I created a simple test for my new Laravel 7 application. But when I run php artisan test I get the following error.
Target [Illuminate\Contracts\View\Factory] is not instantiable.
The error doesn't appear when I go to the page in the browser.
$controller = new HomeController();
$request = Request::create('/', 'GET');
$response = $controller->home($request);
$this->assertEquals(200, $response->getStatusCode());
Although "Just write feature tests" may seem like a cop-out ("They're not unit tests!"), it is sound advice if you do not want to get bogged down by framework-specific knowledge.
You see, this is one of those problems that come from using facades, globals, or static methods. All sorts of things happen outside of your code (and thus your test code) in order for things to work.
The problem
To understand what is going on, you first need to know how Laravel utilizes Containers and Factories in order to glue things together.
Next, what happens is:
Your code (in HomeController::home() calls view() somewhere.
view() calls app() to get the factory that creates Views1
app() calls Container::make
Container::make calls Container::resolve1
Container::resolve decides the Factory needs to be built and calls Container::build to do so
Finally Container::build (using PHP's ReflectionClass figures out that \Illuminate\Contracts\View\Factory can not be Instantiated (as it is an interface) and triggers the error you see.
Or, if you're more of a visual thinker:
The reason that the error is triggered is that the framework expects the container to be configured so that a concrete class is known for abstracts (such as interfaces).
The solution
So now we know what is going on, and we want to create a unit-test, what can we do?
One solution might seem to not use view. Just inject the View class yourself! But if you try to do this, you'll quickly find yourself going down a path that will lead to basically recreating loads of framework code in userland. So not such a good idea.
A better solution would be to mock view() (Now it is really a unit!). But that will still require recreating framework code, only, within the test code. Still not that good.[3]
The easiest thing is to simply configure the Container and tell it which class to use. At this point, you could even mock the View class!
Now, purists might complain that this is not "unit" enough, as your tests will still be calling "real" code outside of the code-under-test, but I disagree...
You are using a framework, so use the framework! If your code uses glue provided by the framework, it makes sense for the test to mirror this behavior. As long as you don't call non-glue code, you'll be fine![4]
So, finally, to give you an idea of how this can be done, an example!
The example
Lets say you have a controller that looks a bit like this:
namespace App\Http\Controllers;
class HomeController extends \Illuminate\Routing\Controller
{
public function home()
{
/* ... */
return view('my.view');
}
}
Then your test[5] might look thus:
namespace Tests\Unit\app\Http\Controllers;
use App\Http\Controllers\HomeController;
use Illuminate\Contracts\View\Factory;
class HomeControllerTest extends \PHPUnit\Framework\TestCase
{
public function testHome()
{
/*/ Arange /*/
$mockFactory = $this->createMock(Factory::class);
app()->instance(Factory::class, $mockFactory);
/*/ Assert /*/
$mockFactory->expects(self::once())
->method('make')
->with('my.view')
;
/*/ Act /*/
(new HomeController())->home();
}
}
A more complex example would be to also create a mock View and have that be returned by the mock factory, but I'll leave that as an exercise to the reader.
Footnotes
app() is asked for the interface Illuminate\Contracts\View\Factory, it is not passed a concrete class name
The reason Container::make does nothing other than call another function is that the method name make is defined by PSR-11 and the Laravel container is PSR compliant.
Also, the Feature test logic provided by Laravel already does all of this for you...
Just don't forget to annotate the test with #uses for the glue that is needed, to avoid warnings when PHPUnit is set to strict mode regarding "risky" tests.
Using a variation of the "Arrange, Act, Assert" pattern
This is not how you test endpoints in Laravel. You should let Laravel instantiate the application as it is already setup in the project, the examples you can see here.
What you already wrote can be rewritten to something like this.
$response = $this->call('GET', route('home')); // insert the correct route
$response->assertOk(); // should be 200
For the test to work, you should extend the TestCase.php, that is located in your test folder.
If you're finding this in The Future and you see #Pothcera's wall of text, here's what you need to know:
The ONLY reason he's doing any of that and the ONLY reason you're seeing this in the first place in a Unit test is because he and you haven't changed from PHPUnit\Framework\TestCase to Tests\TestCase in the test file. This exception doesn't exist when you extend the test case that includes app().
My advice would be to simply extend the correct base test case and move on with your life.

Testing call of multiple methods in phpspec

In the past i always stumbled across a certain problem with phpspec:
Lets assume i have a method which calls multiple methods on another object
class Caller {
public function call(){
$this->receiver->method1();
...
$this->receiver->method2();
}
}
In BDD i would first write a test which makes sure method1 will be called.
function it_calls_method1_of_receiver(Receiver $receiver){
$receiver->method1()->shouldBeCalled();
$this->call();
}
And then i would write the next test to assure method2 will be called.
function it_calls_method2_of_receiver(Receiver $receiver){
$receiver->method2()->shouldBeCalled();
$this->call();
}
But this test fails in phpspec because method1 gets called before method2.
To satisfy phpspec i have to check for both method calls.
function it_calls_method2_of_receiver(Receiver $receiver){
$receiver->method1()->shouldBeCalled();
$receiver->method2()->shouldBeCalled();
$this->call();
}
My problem with that is, that it bloats up every test. In this example it's just one extra line but imagine a method which builds an object with a lot of setters.
I would need to write all setters for every test. It would get quite hard to see the purpose of the test since every test is big and looks the same.
I'm quite sure this is not a problem with phpspec or bdd but rather a problem with my architecture. What would be a better (more testable) way to write this?
For example:
public function handleRequest($request, $endpoint){
$endpoint->setRequest($request);
$endpoint->validate();
$endpoint->handle();
}
Here i validate if an request provides all necessary info for a specific endpoint (or throw an exception) and then handle the request. I choose this pattern to separate validating from the endpoint logic.
Prophecy, the mocking framework used by PhpSpec, is very opinionated. It follows the mockist approach (London School of TDD) which defends that we should describe one behaviour at a time.
A mock is a test, so you want to keep one mock per test. You can mock all the calls, but that will not look elegant. The recommended approach is to separate the behaviour you are testing and select the mock you need for that behaviour, stubbing the rest of the calls. If you see yourself creating loads of stubs in one test that indicates feature envy — you should consider moving the behaviour to the callee, or add a man in the middle.
Say you decide to go ahead and describe the code you have, without refactoring. If you are interested in the second call, as per your example, you should stub the other calls using willReturn, or similar. E.g. $endpoint->setRequest(Argument::type(Request::class))->willReturn() instead of shouldBeCalled().

Mockery "shouldReceive" yet method doesn't exist

I'm trying to understand Tests and Mockery a bit more with Laravel. I have a repository pattern setup, which my controller users. I want to test my basic getAllUsers()method:
public function test_get_all_users_method()
{
$repo = Mockery::mock('Acme\Repositories\User\UserRepository');
$repo->shouldReceive('all')->once()->andReturn('foo');
$controller = new Acme\Controllers\Api\UserController($repo);
$response = $controller->getComponents();
$this->assertEquals('foo', $response);
}
As I understand it, I'm mocking my UserRepository, and I expect my UserRepository to have it's all() method hit. This returns some dummy data and I expect to see this in my response output.
So that works fine. The all() method exists in my Eloquent implementation of the repository. However, if I remove the all() method, the test still passes... Why would it? Surely the test should fail.
If this is normal, I'm struggling to understand why I'd test my controller like this, since I could pass any old method name into it even if it exists or not.
Cheers
That's how mockery operates by default, I like it that way because it allows me to develop by wishful thinking, i.e. I wish my UserRepository interface had an all method.
You can tell mockery to disallow it though, it's a bit ugly, but you can put this in your test bootstrap file:
\Mockery::getConfiguration()->allowMockingNonExistentMethods(false);
You could also set this up to control it with an environment variable or something, so you allow mocking non-existent methods during normal use, but prevent it on your continuous integration run etc.

Autoload a simple DAO in Symfony2+Propel

I've been working on a project and I decided it'd be a good idea to have some sort of, like, DAO, but simplified.
Basically, the only thing I want from it (right now, at least) is to fetch me objects by model name and id. I wrote this very simple piece of code:
class DAO {
public static function get($className,$id) {
$queryName = $className."Query";
if (!class_exists($className) || !class_exists($queryName)) {
return false;
}
$q = $queryName::create()->filterByID($id)->find();
return $q;
}
}
However, I found myself stuck with the implementation. I guess I need to somehow autoload it so that it'll be able to check for the existence of the classes and so that I could use it anywhere inside my app, but I don't know how. Can anyone help me out? Or if there's a better way to do that, I'll appreciate any input.
What you're looking for is a Service.
Definition from the documentation:
Put simply, a Service is any PHP object that performs some sort of
"global" task. It's a purposefully-generic name used in computer
science to describe an object that's created for a specific purpose
(e.g. delivering emails). Each service is used throughout your
application whenever you need the specific functionality it provides.
Defining your class as a service is as simple as this:
app/config/config.yml
...
services:
my_dao:
class: Your\Bundle\DAO
...
Now you can access DAO in your controllers doing something like this:
$dao = $this->get('my_dao');
When you make this call, the Service Container will create an instance of your class and return it. There will always be at most one instance (singleton) and if it's never called, it won't even be instantiated.
I recommend reading the documentation.
Opinion
It seems like you're having trouble adapting to the Symfony way.
If you take a look at The Book you'll see that the Entity Manager in conjunction with your entity's Repository handle most of what DAO's traditionally did. In other words, there's really no need for your DAO class.
For example, fetching any object by id is as easy as:
$om->getRepository('YourBundle:YourModel')->find($id);
Anyway, if you're particularly fond of that approach, you may want to try this project.

Mock frameworks returns class with different name and type

I'm trying to create a mock to satisfy a typehint with this code (Mockery):
return \Mockery::mock('\Contracts\Helpers\iFileSystemWrapper');
or this (PHPUnit):
return $this->getMock('\Contracts\Helpers\iFileSystemWrapper');
But the mock returned is called Mockery\Mock Object or Mock_iFileSystemWrapper_a5f91049. How am I supposed to type check this when it isn't an instance of what I need at all with either framework?
Why exactly is the mock framework trying to load the real class? If I wanted the real class I would include the real class.
This problem has slowed me down so many times when writing tests I'm about to just toss type hinting out the window and check class names instead, or simply use production objects as mocks are a pain to use.
I just experimented with an existing test of my own, and by changing the interface namespace name from one that exists to one that doesn't exist, I got exactly the same as what you describe (using phpunit). My mock object had the class name Mock_ViewInterface_c755461e. When I change it back to the correct interface name, it works fine.
Therefore I would say that either:
You are trying to use an interface name that doesn't exist (e.g. a typo or missing namespace component).
Your library code isn't being loaded for some reason, e.g. autoloading is not setup correctly in your unit test bootstrap.
You need use a special function to check base class.
Somthing like this:
$mock = $this->getMock('MyClass');
$this->assertInstanceOf('MyClass', $mock);

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