Question

我正在使用PHPUnit但很难让它为用作数据存储区的对象创建好的模拟和存根。

示例：

class urlDisplayer {
    private $storage;
    public function __construct(IUrlStorage $storage) { $this->storage = $storage; }
    public function displayUrl($name) {}
    public function displayLatestUrls($count) {}
}

interface IUrlStorage {
    public function addUrl($name, $url);
    public function getUrl($name);
}

class MysqlUrlStorage implements IUrlStorage {
    // saves and retrieves from database
}

class NonPersistentStorage implements IUrlStorage {
    // just stores for this request
}

例如，如何让PHPUnit存根在两个具有不同$ name的调用中返回多个可能的值？

编辑：示例测试：

public function testUrlDisplayerDisplaysLatestUrls {
    // get mock storage and have it return latest x urls so I can test whether
    // UrlDisplayer really shows the latest x
}

在这个测试中，mock应该返回一些url，但是在文档中我只知道如何返回一个值。

Answer 1

您的问题不是很明确 - 但我假设您在询问如何使用phpunit的模拟对象在不同情况下返回不同的值？

PHPUnit的模拟类允许您指定一个自定义函数（即：回调函数/方法） - 它实际上可以无限制地执行。

在下面的示例中，我创建了一个模拟IUrlStorage类，每次调用它时都会返回其存储中的下一个url。

public function setUp()
{
    parent::setUp();
    $this->fixture = new UrlDisplayer(); //change this to however you create your object

    //Create a list of expected URLs for testing across all test cases
    $this->expectedUrls = array(
          'key1' => 'http://www.example.com/url1/'
        , 'key2' => 'http://www.example.net/url2/'
        , 'key3' => 'http://www.example.com/url3/'
    );
}

public function testUrlDisplayerDisplaysLatestUrls {
    //Init        
    $mockStorage = $this->getMock('IUrlStorage');
    $mockStorage->expects($this->any())
        ->method('getUrl')
        ->will( $this->returnCallback(array($this, 'mockgetUrl')) );

    reset($this->expectedUrls); //reset array before testing

    //Actual Tests
    $this->assertGreaterThan(0, count($this->expectedUrls));
    foreach ( $this->expectedUrls as $key => $expected ) {
        $actual = $this->fixture->displayUrl($key);
        $this->assertEquals($expected, $actual);
    }
}

public function mockGetUrl($name)
{
    $value = current($this->expectedUrls);
    next($this->expectedUrls);

    //Return null instead of false when end of array is reached
    return ($value === false) ? null : $value;
}

或者，有时候简单地创建一个模拟必要功能的真实类更容易。通过定义明确的小接口，这一点尤为简单。

在这种特定情况下，我建议使用以下类：

class MockStorage implements IUrlStorage
{
    protected $urls = array();

    public function addUrl($name, $url)
    {
        $this->urls[$name] = $url;
    }

    public function getUrl($name)
    {
        if ( isset($this->urls[$name]) ) {
            return $this->urls[$name];
        }
        return null;
    }
}
?>

然后在您的单元测试类中，您只需像下面那样实例化您的灯具：

public function setUp() {
   $mockStorage = new MockStorage();

   //Add as many expected URLs you want to test for
   $mockStorage->addUrl('name1', 'http://example.com');
   //etc...

   $this->fixture = new UrlDisplayer($mockStorage);
}

用PHP测试数据存储区

1 个答案: