PHPUnit testing Mock's method which takes closure as a param - php

I write a class which populate DI container with services from yaml file. I have problem with testing a below method:
private function parseServices(array $services)
{
foreach ($services as $name => $attr) {
$this->container[$name] = function() use($attr) {
$reflect = new \ReflectionClass($attr["class"]);
$args = $this->parseArguments($attr["arguments"]);
return $reflect->newInstanceArgs($args);
};
}
}
$services is an array with services:
array(
serviceName => array(
class => className,
arguments => array(...)
)
)
A method parseArguments() returns a simple array of arguments for a constructor. For tests $container is a mock. I want to test that container is called one time for every service witch specific parameters. How can I test this? My idea was something like this:
$this->container
->expects($this->at(3))
->method('offsetSet')
->with('demo',$this->callback());
But this doesn't work.
EDIT
The responsibility of this method and even of whole class is populating a container. So maybe the best way to test it is to just check if container is populate correctly? As I wrote in a comment - just don't mock the container but use a concrete implementation. What do you think about it?

Ok, maybe it's not exactly answer to your question, but could be helpful anyway.
I would design this test different. Since you want to test if proper services are being built it would be easier to use some accessor to get 3rd service and check if it is an object of proper class.
... I just saw EDIT ;) - exactly! With properly designed code it's easier to test class from "outside" point of view. In need such wicked mocking only on legacy systems, when i.e can't inject dependencies.
// Original answer
Could you explain what offsetSet is?
From what I see in your test is that you try to assert that
when the method offsetSet is called on $this->container
for the third time
it should be called with two parameters:
'demo' string and
whatever $this->callback() returns (maybe you meant the callback this->callback should be passed as 2nd param, not result of calling it?)

Related

How to mock an aliased class with a method that returns an instance of itself?

I've been successfully using Mockery with PHPUnit tests lately. Yet, there is a dependency in a project I'm currently working that uses static method calls to interact with an API. I'm struggling to test one particular use case and it feels like I'll find other like this during the development roadmap.
Using this class as an example:
namespace Name\Space;
class User
{
/**
* #return \Name\Space\User[]
*/
public static function list(): array
{
// ...
}
public static function create(array $attrs): User
{
// ...
}
}
In case I just want to assert a method returns a primitive type, such as an array:
Mockery::mock('alias:\Name\Space\User')
->shouldReceive('list')
->andReturn([]);
It works fine, primarily because I'm not testing the array contents.
However, I have to call the create method, which returns an instance of the class itself (User). If I do something like this:
$user = new \Name\Space\User();
Mockery::mock('alias:\Name\Space\User')
->shouldReceive('create')
->andReturn($user);
The alias, obviously, won't work because the class was already loaded through the autoloader (composer's, in this case).
Does anyone have a suggestion on how to workaround this?
What about creating User in a closure?
<?php
$user = Mockery::mock('overload:\Name\Space\User')
->shouldReceive('create')
->andReturnUsing(function() {
return new \Name\Space\User();
});
Mocking static stuff is always painful.
I would recommend creating a Proxy object that is calling the static API calls and just returns the API results and inject this object everywhere you need to call the API.
This way it is easy to test by simply mocking the proxy object.
The proxy object itself can then be tested in an end to end test outside of the pure unit test scope.
You can still do more invasive stuff like this
https://www.pagemachine.de/blog/mocking-static-method-calls/?cn-reloaded=1
But writing code that doesn't belong to your unit tests purely to make something testable doesn't feel right to me.

Mock a method within a model method in CakePHP

I am running CakePHP 2.8.X, and am trying to write a unit test for a Model function.
Let's call the model Item, and I'm trying to test its getStatus method.
However, that model makes a call to its find within the getStatus method.
So something like this:
class Item extends Model
{
public function getStatus($id) {
// Calls our `$this->Item-find` method
$item = $this->find('first', [
'fields' => ['status'],
'conditions' => ['Item.id' => $id]
]);
$status = $item['status'];
$new_status = null;
// Some logic below sets `$new_status` based on `$status`
// ...
return $new_status;
}
}
The logic to set "$new_status" is a bit complex, which is why I want to write some tests for it.
However, I'm not entirely sure how to override the find call within Item::getStatus.
Normally when I want to mock a Model's function, I use $this->getMock coupled with method('find')->will($this->returnValue($val_here)), but I don't want to completely mock my Item since I want to test its actual getStatus function.
That is, in my test function, I'm going to be calling:
// This doesn't work since `$this->Item->getStatus` calls out to
// `$this->Item->find`, which my test suite doesn't know how to compute.
$returned_status = $this->Item->getStatus($id);
$this->assertEquals($expected_status, $returned_status);
So how do I communicate to my real Item model within my test that it should override its internal call to its find method?
I knew this had to be an issue others have faced, and it turns out PHPUnit has a very easy way to address this!
This tutorial essentially gave me the answer.
I do need to create a mock, but by only passing in 'find' as the methods I'd like to mock, PHPUnit helpfully leaves all other methods in my Model alone and does not override them.
The relevant part from the above tutorial is:
Passing an array of method names to your getMock second argument produces a mock object where the methods you have identified
Are all stubs,
All return null by default,
Are easily overridable
Whereas methods you did not identify
Are all mocks,
Run the actual code contained within the method when called (emphasis mine),
Do not allow you to override the return value
Meaning, I can take that mocked model, and call my getStatus method directly from it. That method will run its real code, and when it gets to find(), it'll just return whatever I passed into $this->returnValue.
I use a dataProvider to pass in what I want the find method to return, as well as the result to test against in my assertEquals call.
So my test function looks something like:
/**
* #dataProvider provideGetItemStatus
*/
public function testGetItemStatus($item, $status_to_test) {
// Only mock the `find` method, leave all other methods as is
$item_model = $this->getMock('Item', ['find']);
// Override our `find` method (should only be called once)
$item_model
->expects($this->once())
->method('find')
->will($this->returnValue($item));
// Call `getStatus` from our mocked model.
//
// The key part here is I am only mocking the `find` method,
// so when I call `$item_model->getStatus` it is actually
// going to run the real `getStatus` code. The only method
// that will return an overridden value is `find`.
//
// NOTE: the param for `getStatus` doesn't matter since I only use it in my `find` call, which I'm overriding
$result = $item_model->getStatus('dummy_id');
$this->assertEquals($status_to_test, $result);
}
public function provideGetItemStatus() {
return [
[
// $item
['Item' => ['id' = 1, 'status' => 1, /* etc. */]],
// status_to_test
1
],
// etc...
];
}
one way to mock find could be to use a test specific subclass.
You could create a TestItem that extends item and overrides find so it doesn't perform a db call.
Another way could be to encapsulate the new_status logic and unittests it independent of the model

How to test factory classes?

Given this class:
class MyBuilder {
public function build($param1, $param2) {
// build dependencies ...
return new MyClass($dep1, $dep2, $dep3);
}
}
How can I unit test this class?
Unit-testing it means I want to test its behavior, so I want to test it builds my object with the correct dependencies. However, the new instruction is hardcoded and I can't mock it.
For now, I've added the name of the class as a parameter (so I can provide the class name of a mock class), but it's ugly:
class MyBuilder {
public function build($classname, $param1, $param2) {
// build dependencies ...
return new $classname($dep1, $dep2, $dep3);
}
}
Is there a clean solution or design pattern to make my factories testable?
Factories are inherently testable, you are just trying to get too tight of control over the implementation.
You would check that you get an instance of your class via $this->assertInstanceOf(). Then with the resulting object, you would make sure that properties are set properly. For this you could use any public accessor methods or use $this->assertAttribute* methods that are available in PHPUnit.
http://phpunit.de/manual/current/en/writing-tests-for-phpunit.html#writing-tests-for-phpunit.assertions.assertEquals
Many of the common assertions also have the ability to check attributes for protected and private properties.
I wouldn't specify the classname in your parameter list, as your usage is that the factory will only return one type and it is only the dependencies that are changed. Making it return a mock object type is unnecessary and makes your test more complicated.
The test would end up looking like this:
public function testBuild() {
$factory = new MyBuilder();
//I would likely put the following into a data provider
$param1 = 'foo';
$param2 = 'bar';
$depen1 = 'boo';
$depen2 = 'baz';
$depen3 = 'boz';
$object = $factory->build($param1, $param2);
$this->assertInstanceOf('MyClass', $object);
//Check the object definition
//This would change depending on your actual implementation of your class
$this->assertAttributeEquals($depen1, 'attr1', $object);
$this->assertAttributeEquals($depen2, 'attr2', $object);
$this->assertAttributeEquals($depen3, 'attr3', $object);
}
You are now making sure that your factory returns a proper object. First by making sure that it is of the proper type. Then by making sure that it was initialized properly.
You are depending upon the existence of MyClass for the test to pass but that is not a bad thing. Your factory is intended to created MyClass objects so if that class is undefined then your test should definitely fail.
Having failing tests while your developing is also not a bad thing.
So what do you want to test?
so I want to test it builds my object with the correct dependencies.
I do see a problem with this. It's either possible that you can create an object with incorrect dependencies (which should not be the case in the first place or tested in other tests, not with the factory) or you want to test a detail of the factory that you should not test at all.
Otherwise - if it's not mocking the factory what you're looking for - I see no reason why a simple
$actual = $subject->build($param1, $param2);
$this->assertInstanceOf('MyClass', $actual);
would not make it. It tests the behavior of the factory build method, that it returns the correct type.
See as well Open-Close-Principle
For tests, you can just create your MockBuilder which extends from your Builder:
class MyMockBuilder extends MyBuilder {
public function build($param1, $param2) {
// build dependencies ...
return new MyMockClass($dep1, $dep2, $dep3);
}
}
Making the classname a parameter 1:1 seems not practical to me, because it turns the factory over into something different. The creating is a detail of the factory, nothing you externalize. So it should be encapsulated. Hence the MockBuilder for tests. You switch the Factory.
As I see it, you ned to verify two things for that builder:
the correct instance is returned
values, that are injected are the right ones.
Checking instance is the easy part. Verifying values needs a bit of trickery.
The simples way to do this would be altering the autoloader. You need to make sure that when MyClass is requested for autoloader to fetch, instead of /src/app/myclass.php file it loads /test/app/myclass.php, which actually contains a "transparent" mock (where you with simple getters can verify the values).
bad idea
Update:
Also, if you do not want to mess with autoloader, you can just at th top of your myBuilderTest.php file include the mock class file, which contains definition for MyClass.
... this actually seems like a cleaner way.
namespace Foo\Bar;
use PHPUnit_Framework_TestCase;
require TEST_ROOT . '/mocks/myclass.php'
class MyBuilderTest extends PHPUnit_Framework_TestCase
{
public function MyBuilder_verify_injected_params_test()
{
$target = new MyBuilder;
$instance = $target->build('a', 'b');
$this->assertEquals('a', $instance->getFirstConstructorParam();
}
}

How to mock an argument that returns a new class in PHPUnit?

I'm having a problem with a line of code like:
$user->has('roles', ORM::factory('role', array('name' => 'unverified')))
I can mock the first argument, but can only assert that the 2nd argument returns a class. In some classes I make multiple uses of has and need to be able to test them properly. To be clear, I need to confirm that "unverified" was passed into the factory method of the 2nd argument. Any help is much appreciated.
The class I'm testing:
<?php
/**
* Policy class to determine if a user can upload a file.
*/
class Policy_File_Upload extends Policy
{
const NOT_LOGGED_IN = 1;
const NOT_VERIFIED = 2;
public function execute(Model_ACL_User $user, array $extra = NULL)
{
if ($user->can('login'))
{
return self::NOT_LOGGED_IN;
}
elseif ($user->has('roles', ORM::factory('role', array('name' => 'unverified'))))
{
return self::NOT_VERIFIED;
}
return TRUE;
}
}
and the corresponding test:
public function test_guest()
{
// User mock
$user = $this->getMock('Model_User', array('can', 'has'), array(), '', FALSE);
$user->expects($this->any())->method('can')->with('login')->will($this->returnValue(TRUE));
$user->expects($this->any())->method('has')->with('roles', $this->logicalOr
(
))
->will($this->returnCallback(array($this, 'roles')));
$policy = new Policy_File_Upload;
$this->assertSame(Policy_File_Upload::NOT_VERIFIED, $policy->execute($user));
}
You can always go the data-driven route of preparing test data for each case and verify the result of calling the function. In the end, you don't so much care that 'unverified' gets passed to ORM::factory() but rather that the correct result comes out of execute() based on the input.
Testing the implementation details makes the test brittle and difficult to write. If you can test the results instead, your tests won't break when you change how you arrive at the result. It may take longer to put together a data set for all your use cases, but it can generally be shared among tests.
To be clear, I need to confirm that "unverified" was passed into the factory method of the 2nd argument.
<?php
public function execute(Model_ACL_User $user, array $extra = NULL)
[...] ORM::factory('role', array('name' => 'unverified')) [...]
I'm sorry mate, you can't do that as there is no (sane) way to mock out a static method call.
The argument to why this is a problem are similar to one of Sebastian Bergmanns blog post: Testing-Code-That-Uses-Singletons
There are options like runkit that you could choose to replace the "ORM" class at runtime with a mocked version but thats really painfull.
So there are a couple of options:
You could create something like a Policy_File_Upload_Data_Provider that has a ->getRoles method where you put your ORM access. That would allow you to test your business logic nicely and testing that data access class should be a little easier as it doesn't to that much (just accessing the orm).
You could Inject your ORM class (or if that doesn't work out maybe just its name).
Depending on the class its self you should be able to create an instance and call ->factory like it would be a normal method. You could mock that.
If you don't want that just leaving that in there is also a not SO bad option.
Hope that at least gave you an idea/overview.
Additional Links why it's hard to test statics:
Misko Hevery - Flaw: Brittle Global State & Singletons
Kore Nordmann - Static considered harmful
You can actually do verification on parameters passed to mock methods utilizing parameter capturing in the Phake mocking framework for PHP.
public function test_guest()
{
// User mock
$user = Phake::mock('Model_User');
when($user)->can('login')->thenReturn(FALSE);
when($user)->has('roles', $this->anything())->thenGetReturnByLambda(array($this, 'roles'));
$policy = new Policy_File_Upload;
$this->assertSame(Policy_File_Upload::NOT_VERIFIED, $policy->execute($user));
Phake::verify($user)->has('roles', Phake::capture($factoriedRole));
$this->assertEquals('unverified', $factoriedRole->get('name'));
}
This example is assuming that you have the ability to check the name on $factoriedRole, obviously that piece needs to be changed depending on how that ORM stack works.
A small note, I agree with edorian regarding statics. If possible I would always prefer redesigning your code to not require statics, but sometimes that isn't possible, in which case this is a workable solution.
Phake Github Page
Phake Documentation on Parameter Capturing

Pass by reference in a callback when mocking in PHPUnit

I have an interface I want to mock, and mock the behaviour of one of it's methods.
So I have created a callback that mocks the behaviour very simply.
This test passes if I create a new object that is based on this interface, but I would like to mock the interface.
The mocked setUp method is being called fine, and calling getVar('testing') in my callback returns the value. However my assertion fails, because that value isn't available.
It seems that you can't do this in PHPUnit? Unless I am being stupid.
Brief explanation of the code flow; The code in "getVar" calls a method which calls the "setUp" on the added plugin. When it calls "setUp" it passes in "$this". It is $this I am expecting to be passed by reference and which works with a "real" object.
class DefaultRendererTest extends \PHPUnit_Framework_TestCase
{
public function testSetGetVar()
{
$theme = $this->getMock('ThemeInterface');
$plugin = $this->getMock('PluginInterface');
$plugin->expects($this->once())
->method('setUp')
->will($this->returnCallback(function($r){
$r->setVar('testing', "fooBar");
}));
$renderer = new DefaultRenderer($theme, null);
$renderer->addPlugin($plugin);
$this->assertEquals('fooBar',$renderer->getVar('testing'));
}
}
For info here is the interface, the DefaultRenderer implements a RendererInterface
interface PluginInterface
{
function setUp(RendererInterface $renderer);
}
OK, out of interest, I tracked down the issue. It seems that PHPUnit automatically clones the parameters before the actual invocation takes place. I don't see a real reason for this, but maybe there is one. Taking a look at Framework/MockObject/Invocation/Static.php, there is only a single way how you can avoid this (on basis of the built in mock code): Implement a private __clone() method in the DefaultRenderer.
I'd also suggest you ask on IRC or the PHPUnit mailinglist about this behaviour or the mock object library.

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