PHP NullObject

Generates a NullObject from an interface. It was created for testing and AOP.

Installation

composer require --dev koriym/null-object

Getting Started

Instantiate a Null Object from an Interface.

interface FooInterface
{
   public function do(): void;
}

$nullObject = $this->nullObject->newInstance(FooInterface::class);
assert($nullObject instanceof FooInterface);
$nullObject->do(); // nothing's going to happen

newInstance() defines a class with eval, but use save() to save the generated code to a file.

$class = $this->nullObject->save(FooInterface::class, '/path/to/saveDirectory');
assert(new $class instanceof FooInterface);

On the fly

It is also possible to create a null object by simply adding a Null suffix to the interface by registering autoloader, If this doesn't sound too wild to you.

$loader = require __DIR__ . '/vendor/koriym/null-object/autoload.php';
spl_autoload_register($loader);

or add it to autoload-dev in composer.json.

    "autoload-dev": {
        "files": ["./vendor/koriym/null-object/autoload.php"]
    }

You can create Null Object as follows.

$nullClass = FooInterface::class . 'Null'; // add Null suffix to the interface
$foo = new $nullClass;  // instantiate a NullObject
assert($foo instanceof FooInterface);

Note

Inherited interfaces are not yet supported.