Testing

Because Silex is built on top of Symfony2, it is very easy to write functional tests for your application. Functional tests are automated software tests that ensure that your code is working correctly. They go through the user interface, using a fake browser, and mimic the actions a user would do.

Why

If you are not familiar with software tests, you may be wondering why you would need this. Every time you make a change to your application, you have to test it. This means going through all the pages and making sure they are still working. Functional tests save you a lot of time, because they enable you to test your application in usually under a second by running a single command.

For more information on functional testing, unit testing, and automated software tests in general, check out PHPUnit and Bulat Shakirzyanov’s talk on Clean Code.

PHPUnit

PHPUnit is the de-facto standard testing framework for PHP. It was built for writing unit tests, but it can be used for functional tests too. You write tests by creating a new class, that extends the PHPUnit_Framework_TestCase. Your test cases are methods prefixed with test:

class ContactFormTest extends PHPUnit_Framework_TestCase
{
    public function testInitialPage()
    {
        ...
    }
}

In your test cases, you do assertions on the state of what you are testing. In this case we are testing a contact form, so we would want to assert that the page loaded correctly and contains our form:

public function testInitialPage()
{
    $statusCode = ...
    $pageContent = ...

    $this->assertEquals(200, $statusCode);
    $this->assertContains('Contact us', $pageContent);
    $this->assertContains('<form', $pageContent);
}

Here you see some of the available assertions. There is a full list available in the Writing Tests for PHPUnit section of the PHPUnit documentation.

WebTestCase

Symfony2 provides a WebTestCase class that can be used to write functional tests. The Silex version of this class is Silex\WebTestCase, and you can use it by making your test extend it:

use Silex\WebTestCase;

class ContactFormTest extends WebTestCase
{
    ...
}

Note

To make your application testable, you need to make sure you follow “Reusing applications” instructions from Usage.

For your WebTestCase, you will have to implement a createApplication method, which returns your application. It will probably look like this:

public function createApplication()
{
    return require __DIR__.'/path/to/app.php';
}

Make sure you do not use require_once here, as this method will be executed before every test.

Tip

By default, the application behaves in the same way as when using it from a browser. But when an error occurs, it is sometimes easier to get raw exceptions instead of HTML pages. It is rather simple if you tweak the application configuration in the createApplication() method like follows:

public function createApplication()
{
    $app = require __DIR__.'/path/to/app.php';
    $app['debug'] = true;
    $app['exception_handler']->disable();

    return $app;
}

Tip

If your application use sessions, set session.test to true to simulate sessions:

public function createApplication()
{
    // ...

    $this->app['session.test'] = true;

    // ...
}

The WebTestCase provides a createClient method. A client acts as a browser, and allows you to interact with your application. Here’s how it works:

public function testInitialPage()
{
    $client = $this->createClient();
    $crawler = $client->request('GET', '/');

    $this->assertTrue($client->getResponse()->isOk());
    $this->assertCount(1, $crawler->filter('h1:contains("Contact us")'));
    $this->assertCount(1, $crawler->filter('form'));
    ...
}

There are several things going on here. You have both a Client and a Crawler.

You can also access the application through $this->app.

Client

The client represents a browser. It holds your browsing history, cookies and more. The request method allows you to make a request to a page on your application.

Note

You can find some documentation for it in the client section of the testing chapter of the Symfony2 documentation.

Crawler

The crawler allows you to inspect the content of a page. You can filter it using CSS expressions and lots more.

Note

You can find some documentation for it in the crawler section of the testing chapter of the Symfony2 documentation.

Configuration

The suggested way to configure PHPUnit is to create a phpunit.xml.dist file, a tests folder and your tests in tests/YourApp/Tests/YourTest.php. The phpunit.xml.dist file should look like this:

<?xml version="1.0" encoding="UTF-8"?>
<phpunit backupGlobals="false"
         backupStaticAttributes="false"
         colors="true"
         convertErrorsToExceptions="true"
         convertNoticesToExceptions="true"
         convertWarningsToExceptions="true"
         processIsolation="false"
         stopOnFailure="false"
         syntaxCheck="false"
>
    <testsuites>
        <testsuite name="YourApp Test Suite">
            <directory>./tests/</directory>
        </testsuite>
    </testsuites>
</phpunit>

You can also configure a bootstrap file for autoloading and whitelisting for code coverage reports.

Your tests/YourApp/Tests/YourTest.php should look like this:

namespace YourApp\Tests;

use Silex\WebTestCase;

class YourTest extends WebTestCase
{
    public function createApplication()
    {
        return require __DIR__.'/../../../app.php';
    }

    public function testFooBar()
    {
        ...
    }
}

Now, when running phpunit on the command line, your tests should run.