The PHPUnit Bridge

The PHPUnit Bridge

The PHPUnit Bridge

The PHPUnit Bridge provides utilities to report legacy tests and usage of deprecated code and helpers for mocking native functions related to time, DNS and class existence.

It comes with the following features:

Forces the tests to use a consistent locale (C) (if you create locale-sensitive tests, use PHPUnit’s `setLocale() method);
Auto-register class_exists to load Doctrine annotations (when used);
It displays the whole list of deprecated features used in the application;
Displays the stack trace of a deprecation on-demand;
Provides a ClockMock, DnsMock and ClassExistsMock classes for tests sensitive to time, network or class existence;
Provides a modified version of PHPUnit that allows 1. separating the dependencies of your app from those of phpunit to prevent any unwanted constraints to apply; 2. running tests in parallel when a test suite is split in several phpunit.xml files; 3. recording and replaying skipped tests;
It allows to create tests that are compatible with multiple PHPUnit versions (because it provides polyfills for missing methods, namespaced aliases for non-namespaced classes, etc.).

Installation

$ composer require --dev symfony/phpunit-bridge

Note

If you install this component outside of a Symfony application, you must require the vendor/autoload.php file in your code to enable the class autoloading mechanism provided by Composer. Read this article for more details.

Note

The PHPUnit bridge is designed to work with all maintained versions of Symfony components, even across different major versions of them. You should always use its very latest stable major version to get the most accurate deprecation report.

If you plan to Deprecation Notices at Autoloading Time and use the regular PHPUnit script (not the modified PHPUnit script provided by Symfony), you have to register a new test listener called SymfonyTestsListener:

<!-- http://phpunit.de/manual/6.0/en/appendixes.configuration.html -->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/6.0/phpunit.xsd"
>
    <!-- ... -->
    <listeners>
        <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener"/>
    </listeners>
</phpunit>

Usage

Running Tests in Parallel

The modified PHPUnit script allows running tests in parallel by providing a directory containing multiple test suites with their own phpunit.xml.dist.

├── tests/
│   ├── Functional/
│   │   ├── ...
│   │   └── phpunit.xml.dist
│   ├── Unit/
│   │   ├── ...
│   │   └── phpunit.xml.dist

$ ./vendor/bin/simple-phpunit tests/

The modified PHPUnit script will recursively go through the provided directory, up to a depth of 3 subdirectories or the value specified by the environment variable SYMFONY_PHPUNIT_MAX_DEPTH, looking for phpunit.xml.dist files and then running each suite it finds in parallel, collecting their output and displaying each test suite’s results in their own section.

Trigger Deprecation Notices

Deprecation notices can be triggered by using:

@trigger_error('Your deprecation message', E_USER_DEPRECATED);

You can also require the symfony/deprecation-contracts package that provides a global `trigger_deprecation() function for this usage.

Without the @-silencing operator, users would need to opt-out from deprecation notices. Silencing by default swaps this behavior and allows users to opt-in when they are ready to cope with them (by adding a custom error handler like the one provided by this bridge). When not silenced, deprecation notices will appear in the Unsilenced section of the deprecation report.

Mark Tests as Legacy

There are three ways to mark a test as legacy:

(Recommended) Add the @group legacy annotation to its class or method;
Make its class name start with the Legacy prefix;
Make its method name start with testLegacy*() instead oftest*().

Note

If your data provider calls code that would usually trigger a deprecation, you can prefix its name with provideLegacy or getLegacy to silence these deprecations. If your data provider does not execute deprecated code, it is not required to choose a special naming just because the test being fed by the data provider is marked as legacy.

Also be aware that choosing one of the two legacy prefixes will not mark tests as legacy that make use of this data provider. You still have to mark them as legacy tests explicitly.

Configuration

In case you need to inspect the stack trace of a particular deprecation triggered by your unit tests, you can set the SYMFONY_DEPRECATIONS_HELPER environment variable to a regular expression that matches this deprecation’s message, enclosed with /. For example, with:

<!-- http://phpunit.de/manual/6.0/en/appendixes.configuration.html -->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/6.0/phpunit.xsd"
>
    <!-- ... -->
    <php>
        <server name="KERNEL_CLASS" value="App\Kernel"/>
        <env name="SYMFONY_DEPRECATIONS_HELPER" value="/foobar/"/>
    </php>
</phpunit>

PHPUnit will stop your test suite once a deprecation notice is triggered whose message contains the "foobar" string.

Making Tests Fail

By default, any non-legacy-tagged or any non-@-silenced deprecation notices will make tests fail. Alternatively, you can configure an arbitrary threshold by setting SYMFONY_DEPRECATIONS_HELPER to max[total]=320 for instance. It will make the tests fails only if a higher number of deprecation notices is reached (0 is the default value).

You can have even finer-grained control by using other keys of the max array, which are self, direct, and indirect. The SYMFONY_DEPRECATIONS_HELPER environment variable accepts a URL-encoded string, meaning you can combine thresholds and any other configuration setting, like this: SYMFONY_DEPRECATIONS_HELPER='max[total]=42&max[self]=0&verbose=0'

Internal deprecations

When you maintain a library, having the test suite fail as soon as a dependency introduces a new deprecation is not desirable, because it shifts the burden of fixing that deprecation to any contributor that happens to submit a pull request shortly after a new vendor release is made with that deprecation.

To mitigate this, you can either use tighter requirements, in the hope that dependencies will not introduce deprecations in a patch version, or even commit the composer.lock file, which would create another class of issues. Libraries will often use SYMFONY_DEPRECATIONS_HELPER=max[total]=999999 because of this. This has the drawback of allowing contributions that introduce deprecations but:

forget to fix the deprecated calls if there are any;
forget to mark appropriate tests with the @group legacy annotations.

By using SYMFONY_DEPRECATIONS_HELPER=max[self]=0, deprecations that are triggered outside the vendors directory will be accounted for separately, while deprecations triggered from a library inside it will not (unless you reach 999999 of these), giving you the best of both worlds.

Direct and Indirect Deprecations

When working on a project, you might be more interested in max[direct]. Let’s say you want to fix deprecations as soon as they appear. A problem many developers experience is that some dependencies they have tend to lag behind their own dependencies, meaning they do not fix deprecations as soon as possible, which means you should create a pull request on the outdated vendor, and ignore these deprecations until your pull request is merged.

The max[direct] config allows you to put a threshold on direct deprecations only, allowing you to notice when your code is using deprecated APIs, and to keep up with the changes. You can still use max[indirect] if you want to keep indirect deprecations under a given threshold.

Here is a summary that should help you pick the right configuration:

Value	Recommended situation
max[total]=0	Recommended for actively maintained projects with robust/no dependencies
max[direct]=0	Recommended for projects with dependencies that fail to keep up with new deprecations.
max[self]=0	Recommended for libraries that use the deprecation system themselves and cannot afford to use one of the modes above.

Disabling the Verbose Output

By default, the bridge will display a detailed output with the number of deprecations and where they arise. If this is too much for you, you can use SYMFONY_DEPRECATIONS_HELPER=verbose=0 to turn the verbose output off.

Disabling the Deprecation Helper

Set the SYMFONY_DEPRECATIONS_HELPER environment variable to disabled=1 to completely disable the deprecation helper. This is useful to make use of the rest of features provided by this component without getting errors or messages related to deprecations.

Deprecation Notices at Autoloading Time

By default, the PHPUnit Bridge uses DebugClassLoader from the ErrorHandler component to throw deprecation notices at class autoloading time. This can be disabled with the debug-class-loader option.

<!-- phpunit.xml.dist -->
<!-- ... -->
<listeners>
    <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener">
        <arguments>
            <array>
                <!-- set this option to 0 to disable the DebugClassLoader integration -->
                <element key="debug-class-loader"><integer>0</integer></element>
            </array>
        </arguments>
    </listener>
</listeners>

New in version 4.2: The DebugClassLoader integration was introduced in Symfony 4.2.

Write Assertions about Deprecations

When adding deprecations to your code, you might like writing tests that verify that they are triggered as required. To do so, the bridge provides the @expectedDeprecation annotation that you can use on your test methods. It requires you to pass the expected message, given in the same format as for the PHPUnit’s assertStringMatchesFormat() method. If you expect more than one deprecation message for a given test method, you can use the annotation several times (order matters):

/**
 * @group legacy
 * @expectedDeprecation This "%s" method is deprecated.
 * @expectedDeprecation The second argument of the "%s" method is deprecated.
 */
public function testDeprecatedCode()
{
    @trigger_error('This "Foo" method is deprecated.', E_USER_DEPRECATED);
    @trigger_error('The second argument of the "Bar" method is deprecated.', E_USER_DEPRECATED);
}

Display the Full Stack Trace

By default, the PHPUnit Bridge displays only deprecation messages. To show the full stack trace related to a deprecation, set the value of SYMFONY_DEPRECATIONS_HELPER to a regular expression matching the deprecation message.

For example, if the following deprecation notice is thrown:

1x: Doctrine\Common\ClassLoader is deprecated.
  1x in EntityTypeTest::setUp from Symfony\Bridge\Doctrine\Tests\Form\Type

Running the following command will display the full stack trace:

$ SYMFONY_DEPRECATIONS_HELPER='/Doctrine\\Common\\ClassLoader is deprecated\./' ./vendor/bin/simple-phpunit

Testing with Multiple PHPUnit Versions

When testing a library that has to be compatible with several versions of PHP, the test suite cannot use the latest versions of PHPUnit because:

PHPUnit 8 deprecated several methods in favor of other methods which are not available in older versions (e.g. PHPUnit 4);
PHPUnit 8 added the void return type to the `setUp() method, which is not compatible with PHP 5.5;
PHPUnit switched to namespaced classes starting from PHPUnit 6, so tests must work with and without namespaces.

Polyfills for the Unavailable Methods

New in version 4.4: This feature was introduced in Symfony 4.4.

When using the simple-phpunit script, PHPUnit Bridge injects polyfills for most methods of the TestCase and Assert classes (e.g. expectException(),expectExceptionMessage(), `assertContainsEquals(), etc.). This allows writing test cases using the latest best practices while still remaining compatible with older PHPUnit versions.

Removing the Void Return Type

New in version 4.4: This feature was introduced in Symfony 4.4.

When running the simple-phpunit script with the SYMFONY_PHPUNIT_REMOVE_RETURN_TYPEHINT environment variable set to 1, the PHPUnit bridge will alter the code of PHPUnit to remove the return type (introduced in PHPUnit 8) from setUp(),tearDown(), setUpBeforeClass() andtearDownAfterClass() methods. This allows you to write a test compatible with both PHP 5 and PHPUnit 8.

Alternatively, you can use the trait Symfony\Bridge\PhpUnit\SetUpTearDownTrait, which provides the right signature for the setUp(),tearDown(), setUpBeforeClass() andtearDownAfterClass() methods and delegates the call to the doSetUp(),doTearDown(), doSetUpBeforeClass() anddoTearDownAfterClass() methods:

use PHPUnit\Framework\TestCase;
use Symfony\Bridge\PhpUnit\SetUpTearDownTrait;
class MyTest extends TestCase
{
    // when using the SetUpTearDownTrait, methods like doSetUp() can
    // be defined with and without the 'void' return type, as you wish
    use SetUpTearDownTrait;
    private function doSetUp()
    {
        // ...
    }
    protected function doSetUp(): void
    {
        // ...
    }
}

Using Namespaced PHPUnit Classes

New in version 4.4: This feature was introduced in Symfony 4.4.

The PHPUnit bridge adds namespaced class aliases for most of the PHPUnit classes declared without namespaces (e.g. PHPUnit_Framework_Assert), allowing you to always use the namespaced class declaration even when the test is executed with PHPUnit 4.

Time-sensitive Tests

Use Case

If you have this kind of time-related tests:

use PHPUnit\Framework\TestCase;
use Symfony\Component\Stopwatch\Stopwatch;
class MyTest extends TestCase
{
    public function testSomething()
    {
        $stopwatch = new Stopwatch();
        $stopwatch->start('event_name');
        sleep(10);
        $duration = $stopwatch->stop('event_name')->getDuration();
        $this->assertEquals(10000, $duration);
    }
}

You calculated the duration time of your process using the Stopwatch utilities to profile Symfony applications. However, depending on the load of the server or the processes running on your local machine, the $duration could for example be 10.000023s instead of 10s.

This kind of tests are called transient tests: they are failing randomly depending on spurious and external circumstances. They are often cause trouble when using public continuous integration services like Travis CI.

Clock Mocking

The Symfony\Bridge\PhpUnit\ClockMock class provided by this bridge allows you to mock the PHP’s built-in time functions time(),microtime(), sleep(),usleep() and gmdate(). Additionally the functiondate() is mocked so it uses the mocked time if no timestamp is specified.

Other functions with an optional timestamp parameter that defaults to time() will still use the system time instead of the mocked time. This means that you may need to change some code in your tests. For example, instead ofnew DateTime(), you should use DateTime::createFromFormat('U', time()) to use the mockedtime() function.

To use the ClockMock class in your test, add the @group time-sensitive annotation to its class or methods. This annotation only works when executing PHPUnit using the vendor/bin/simple-phpunit script or when registering the following listener in your PHPUnit configuration:

<!-- phpunit.xml.dist -->
<!-- ... -->
<listeners>
    <listener class="\Symfony\Bridge\PhpUnit\SymfonyTestsListener"/>
</listeners>

Note

If you don’t want to use the @group time-sensitive annotation, you can register the ClockMock class manually by calling ClockMock::register(__CLASS__) andClockMock::withClockMock(true) before the test and `ClockMock::withClockMock(false) after the test.

As a result, the following is guaranteed to work and is no longer a transient test:

use PHPUnit\Framework\TestCase;
use Symfony\Component\Stopwatch\Stopwatch;
/**
 * @group time-sensitive
 */
class MyTest extends TestCase
{
    public function testSomething()
    {
        $stopwatch = new Stopwatch();
        $stopwatch->start('event_name');
        sleep(10);
        $duration = $stopwatch->stop('event_name')->getDuration();
        $this->assertEquals(10000, $duration);
    }
}

And that’s all!

Caution

Time-based function mocking follows the PHP namespace resolutions rules so “fully qualified function calls” (e.g `\time()) cannot be mocked.

The @group time-sensitive annotation is equivalent to calling ClockMock::register(MyTest::class). If you want to mock a function used in a different class, do it explicitly usingClockMock::register(MyClass::class):

// the class that uses the time() function to be mocked
namespace App;
class MyClass
{
    public function getTimeInHours()
    {
        return time() / 3600;
    }
}
// the test that mocks the external time() function explicitly
namespace App\Tests;
use App\MyClass;
use PHPUnit\Framework\TestCase;
use Symfony\Bridge\PhpUnit\ClockMock;
/**
 * @group time-sensitive
 */
class MyTest extends TestCase
{
    public function testGetTimeInHours()
    {
        ClockMock::register(MyClass::class);
        $my = new MyClass();
        $result = $my->getTimeInHours();
        $this->assertEquals(time() / 3600, $result);
    }
}

Tip

An added bonus of using the ClockMock class is that time passes instantly. Using PHP’s sleep(10) will make your test wait for 10 actual seconds (more or less). In contrast, theClockMock` class advances the internal clock the given number of seconds without actually waiting that time, so your test will execute 10 seconds faster.

DNS-sensitive Tests

Tests that make network connections, for example to check the validity of a DNS record, can be slow to execute and unreliable due to the conditions of the network. For that reason, this component also provides mocks for these PHP functions:

Use Case

Consider the following example that uses the checkMX option of the Email constraint to test the validity of the email domain:

use PHPUnit\Framework\TestCase;
use Symfony\Component\Validator\Constraints\Email;
class MyTest extends TestCase
{
    public function testEmail()
    {
        $validator = ...;
        $constraint = new Email(['checkMX' => true]);
        $result = $validator->validate('[email protected]', $constraint);
        // ...
    }
}

In order to avoid making a real network connection, add the @dns-sensitive annotation to the class and use the `DnsMock::withMockedHosts() to configure the data you expect to get for the given hosts:

use PHPUnit\Framework\TestCase;
use Symfony\Component\Validator\Constraints\Email;
/**
 * @group dns-sensitive
 */
class MyTest extends TestCase
{
    public function testEmails()
    {
        DnsMock::withMockedHosts(['example.com' => [['type' => 'MX']]]);
        $validator = ...;
        $constraint = new Email(['checkMX' => true]);
        $result = $validator->validate('[email protected]', $constraint);
        // ...
    }
}

The `withMockedHosts() method configuration is defined as an array. The keys are the mocked hosts and the values are arrays of DNS records in the same format returned by dns_get_record, so you can simulate diverse network conditions:

DnsMock::withMockedHosts([
    'example.com' => [
        [
            'type' => 'A',
            'ip' => '1.2.3.4',
        ],
        [
            'type' => 'AAAA',
            'ipv6' => '::12',
        ],
    ],
]);

Class Existence Based Tests

Tests that behave differently depending on existing classes, for example Composer’s development dependencies, are often hard to test for the alternate case. For that reason, this component also provides mocks for these PHP functions:

Use Case

Consider the following example that relies on the Vendor\DependencyClass to toggle a behavior:

use Vendor\DependencyClass;
class MyClass
{
    public function hello(): string
    {
        if (class_exists(DependencyClass::class)) {
            return 'The dependency behavior.';
        }
        return 'The default behavior.';
    }
}

A regular test case for MyClass (assuming the development dependencies are installed during tests) would look like:

use MyClass;
use PHPUnit\Framework\TestCase;
class MyClassTest extends TestCase
{
    public function testHello()
    {
        $class = new MyClass();
        $result = $class->hello(); // "The dependency behavior."
        // ...
    }
}

In order to test the default behavior instead use the `ClassExistsMock::withMockedClasses() to configure the expected classes, interfaces and/or traits for the code to run:

use MyClass;
use PHPUnit\Framework\TestCase;
use Vendor\DependencyClass;
class MyClassTest extends TestCase
{
    // ...
    public function testHelloDefault()
    {
        ClassExistsMock::register(MyClass::class);
        ClassExistsMock::withMockedClasses([DependencyClass::class => false]);
        $class = new MyClass();
        $result = $class->hello(); // "The default behavior."
        // ...
    }
}

Troubleshooting

The @group time-sensitive and @group dns-sensitive annotations work “by convention” and assume that the namespace of the tested class can be obtained just by removing the Tests\ part from the test namespace. I.e. if your test cases fully-qualified class name (FQCN) is App\Tests\Watch\DummyWatchTest, it assumes the tested class namespace is App\Watch.

If this convention doesn’t work for your application, configure the mocked namespaces in the phpunit.xml file, as done for example in the HttpKernel Component:

<!-- http://phpunit.de/manual/4.1/en/appendixes.configuration.html -->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/4.1/phpunit.xsd"
>
    <!-- ... -->
    <listeners>
        <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener">
            <arguments>
                <array>
                    <element key="time-sensitive"><string>Symfony\Component\HttpFoundation</string></element>
                </array>
            </arguments>
        </listener>
    </listeners>
</phpunit>

Under the hood, a PHPUnit listener injects the mocked functions in the tested classes’ namespace. In order to work as expected, the listener has to run before the tested class ever runs.

By default, the mocked functions are created when the annotation are found and the corresponding tests are run. Depending on how your tests are constructed, this might be too late.

You can either:

Declare the namespaces of the tested classes in your phpunit.xml.dist;
Register the namespaces at the end of the config/bootstrap.php file.

<!-- phpunit.xml.dist -->
<!-- ... -->
<listeners>
    <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener">
            <arguments>
                <array>
                    <element key="time-sensitive"><string>Acme\MyClassTest</string></element>
                </array>
            </arguments>
        </listener>
</listeners>

// config/bootstrap.php
use Symfony\Bridge\PhpUnit\ClockMock;
// ...
if ('test' === $_SERVER['APP_ENV']) {
    ClockMock::register('Acme\\MyClassTest\\');
}

Modified PHPUnit script

This bridge provides a modified version of PHPUnit that you can call by using its bin/simple-phpunit command. It has the following features:

Works with a standalone vendor directory that doesn’t conflict with yours;
Does not embed prophecy to prevent any conflicts with its dependencies;
Collects and replays skipped tests when the SYMFONY_PHPUNIT_SKIPPED_TESTS env var is defined: the env var should specify a file name that will be used for storing skipped tests on a first run, and replay them on the second run;
Parallelizes test suites execution when given a directory as argument, scanning this directory for phpunit.xml.dist files up to SYMFONY_PHPUNIT_MAX_DEPTH levels (specified as an env var, defaults to 3);

The script writes the modified PHPUnit it builds in a directory that can be configured by the SYMFONY_PHPUNIT_DIR env var, or in the same directory as the simple-phpunit if it is not provided. It’s also possible to set this env var in the phpunit.xml.dist file.

By default, these are the PHPUnit versions used depending on the installed PHP versions:

Installed PHP version	PHPUnit version used by default
PHP <= 5.5	PHPUnit 4.8
PHP 5.6	PHPUnit 5.7
PHP 7.0	PHPUnit 6.5
PHP 7.1	PHPUnit 7.5
PHP >= 7.2	PHPUnit 8.3

If you have installed the bridge through Composer, you can run it by calling e.g.:

$ vendor/bin/simple-phpunit

Tip

It’s possible to change the base version of PHPUnit by setting the SYMFONY_PHPUNIT_VERSION env var in the phpunit.xml.dist file (e.g. <server name="SYMFONY_PHPUNIT_VERSION" value="5.5"/>). This is the preferred method as it can be committed to your version control repository.

It’s also possible to set SYMFONY_PHPUNIT_VERSION as a real env var (not defined in a dotenv file).

Tip

If you still need to use prophecy (but not symfony/yaml), then set the SYMFONY_PHPUNIT_REMOVE env var to symfony/yaml.

It’s also possible to set this env var in the phpunit.xml.dist file.

Code Coverage Listener

By default, the code coverage is computed with the following rule: if a line of code is executed, then it is marked as covered. The test which executes a line of code is therefore marked as “covering the line of code”. This can be misleading.

Consider the following example:

class Bar
{
    public function barMethod()
    {
        return 'bar';
    }
}
class Foo
{
    private $bar;
    public function __construct(Bar $bar)
    {
        $this->bar = $bar;
    }
    public function fooMethod()
    {
        $this->bar->barMethod();
        return 'bar';
    }
}
class FooTest extends PHPUnit\Framework\TestCase
{
    public function test()
    {
        $bar = new Bar();
        $foo = new Foo($bar);
        $this->assertSame('bar', $foo->fooMethod());
    }
}

The FooTest::test method executes every single line of code of both Foo and Bar classes, but Bar is not truly tested. The CoverageListener aims to fix this behavior by adding the appropriate @covers annotation on each test class.

If a test class already defines the @covers annotation, this listener does nothing. Otherwise, it tries to find the code related to the test by removing the Test part of the classname: My\Namespace\Tests\FooTest -> My\Namespace\Foo.

Installation

Add the following configuration to the phpunit.xml.dist file:

<!-- http://phpunit.de/manual/6.0/en/appendixes.configuration.html -->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/6.0/phpunit.xsd"
>
    <!-- ... -->
    <listeners>
        <listener class="Symfony\Bridge\PhpUnit\CoverageListener"/>
    </listeners>
</phpunit>

If the logic used to find the related code is too simple or doesn’t work for your application, you can use your own SUT (System Under Test) solver:

<listeners>
    <listener class="Symfony\Bridge\PhpUnit\CoverageListener">
        <arguments>
            <string>My\Namespace\SutSolver::solve</string>
        </arguments>
    </listener>
</listeners>

The My\Namespace\SutSolver::solve can be any PHP callable and receives the current test as its first argument.

Finally, the listener can also display warning messages when the SUT solver does not find the SUT:

<listeners>
    <listener class="Symfony\Bridge\PhpUnit\CoverageListener">
        <arguments>
            <null/>
            <boolean>true</boolean>
        </arguments>
    </listener>
</listeners>

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.