PHPUnit确保特性满足接口

Let's look at the code in psr/log, in particular:

• LoggerAwareTrait
• LoggerAwareInterface

As you know, a trait cannot implement an interface, so these two parts need a class to be successfully connected together.

Let's say I cover testing of the trait (it's relatively easy via PHPUnit's getMockForTrait). The next thing to test is that I want to prove that the trait satisfies the interface.

In terms of code, it looks simple enough:

public function testThatTraitSatisfiesInterface()
{
    $className = 'test_class_' . uniqid();
    $classCode = sprintf(
        'class %s implements %s { use %s; }',
        $className,
        LoggerAwareInterface::class,
        LoggerAwareTrait::class
    );

    eval($classCode); // ewww :see_no_evil:
    new $className(); // no errors? good, test successful
}

A have a few concerns here:

• I'd like to avoid eval() as much as possible (even if I know that it's what drives PHPUnit anyway), but..
• I'd rather use PHPUnit's functionality if at all possible

So the big question is, are there any alternatives?

How about just creating the class as a test asset:

namespace Foo\Bar\Test\Asset;

use Psr\Log;

final class LoggerAware implements Log\LoggerAwareInterface
{
    use Log\LoggerAwareTrait;
}

And then asserting it implements the interface:

namespace Foo\Bar\Test;

use PhpUnit\Framework;
use Psr\Log;

final class LoggerAwareTest extends Framework\TestCase
{
    public function testImplementsLoggerAwareInterface()
    {
        $loggerAware = new Asset\LoggerAware();

        $this->assertInstanceOf(Log\LoggerAwareInterface::class, $loggerAware);
    }
}