When function-mocker is overkill.
<?php
use PHPUnit\Framework\TestCase;
use PHPUnit\Framework\Assert;
use function tad\FunctionMockerLe\define;
use function tad\FunctionMockerLe\defineWithMap;
use function tad\FunctionMockerLe\defineWithValueMap;
use function tad\FunctionMockerLe\defineAll;
use function tad\FunctionMockerLe\undefineAll;
class MyOrmTest extends TestCase {
public function test_query_parameters_are_preserved(){
// define a non existing function
define('get_posts', function(array $args){
Assert::assertEquals(['post_type' => 'book','paginated' => 2, 'posts_per_page' => 6], $args);
return [];
});
$orm = new MyOrm('book');
$orm->query()
->page(2)
->perPage(6)
->fetch();
}
public function test_users_cannot_fetch_posts_they_cannot_read(){
// define a number of functions using a <function> => <callback> map
defineWithMap([
'is_user_logged_in' => function(){
return true;
},
'get_posts' => function(){
return[
['ID' => 1, 'post_title' => 'One'],
['ID' => 2, 'post_title' => 'Two'],
['ID' => 3, 'post_title' => 'Three'],
['ID' => 4, 'post_title' => 'Four']
];
},
'current_user_can' => function($cap, $id){
// a post ID to 'can' map
$map = [
1 => true,
2 => true,
3 => false,
4 => true
];
return $map($id);
}
]);
$orm = new MyOrm('book');
$books = $orm->query()
->fetch();
$expected = [
['ID' => 1, 'post_title' => 'One'],
['ID' => 2, 'post_title' => 'Two'],
['ID' => 4, 'post_title' => 'Four']
];
$this->assertEquals($expected, $books);
}
public function test_sticky_posts_are_not_prepended_if_not_home_archive_or_tag(){
// define a number of functions all with the same callback...
defineAll(['is_home', 'is_archive', 'is_tag'], function(){
return false;
});
define('get_posts', function(array $args){
Assert::arrayHasKey('ignore_sticky_posts,', $args);
Assert::assertEquals('1', $args['ignore_sticky_posts']);
});
$orm = new MyOrm('book');
$orm->query()->fetch();
// ...and then redefine them
defineWithValueMap([
'is_home' => true,
'is_archive' => false,
'is_tag' => false
]);
// redefine as needed
define('get_posts', function(array $args){
Assert::arrayNotHasKey('ignore_sticky_posts,', $args);
});
$orm->query()->fetch();
}
public function tearDown()
{
// undefine all the functions after each test to avoid test dependencies
undefineAll();
}
}
Use Composer to require the library in the project
composer require --dev lucatume/function-mocker-le
The library provides a lightweight and dependency-free function mocking solution.
The reason one might want to mock a function in the tests is to test any code that depends on a framework based on functions (e.g. WordPress).
The difference between this library and function-mocker is that this will only work when none of the function it defines are defined during the execution; function-mocker will allow instead monkey-patching the functions at runtime even if those are already defined.
Where function mocker depends on the Patchwork library to allow for user-land monkey-patching this library has a minimal code footprint and only provides a handful of functions.
Patchwork or function-mocker should be used if really loading the mocked functions source cannot be avoided in the tests.
The library core function is the define($function, $callback)
one: it defines a function and sets its content to a callback; in its basic usage it allows setting up a mocked function return value in the tests:
public function test_current_user_can(){
tad\FunctionMockerLe\define('current_user_can', function(){
return true;
});
$this->assertTrue(current_user_can('read_posts'));
}
The $callback
argument can be a callable
of any kind, in this example I'm using the Prophecy mocking engine to use set complex expectations:
public function test_prophecy(){
$pr = $this->prophesize(User::class);
$pr->can('read_posts')->shouldBeCalled();
$pr->can('edit_posts')->shouldNotBeCalled();
tad\FunctionMockerLe\define('current_user_can', [$pr->reveal(), 'can']);
current_user_can('read_posts');
current_user_can('edit_posts'); // this will trigger a failure: not expected
current_user_can('read_posts');
}
Relying on basic assertions provided by hte PhpUnit library is another option:
public function test_prophecy(){
tad\FunctionMockerLe\define('current_user_can', function($cap){
PHPUnit\Framework\Assert::assertNotEquals('edit_posts', $cap);
});
current_user_can('read_posts');
current_user_can('edit_posts'); // this will trigger a failure: not expected
current_user_can('read_posts');
}
Where function-mocker tries to provide a feature-reach solution to the problem of mocking functions (and more); this project tries to provide just a basic starting point with no opinionated choices about its usage.
The other functions provided by the libary are just sugar wrappers around the define
core; see the example and the /tests
folder for clarity.
The undefine($function)
and undefineAll()
methods will "undefine" functions managed by the Function Mocker LE library; in this context "undefine" means that calling the undefined function will trhow an tad\FunctionMockerLe\UndefinedFunctionException
.
To run the tests install the composer dependencies and run PHPUnit:
composer install
vendor/bin/phpunit