Subversion-Projekte lars-tiefland.laravel_shop

.. index::

    single: Getting Started; Simple Example

Simple Example

==============

Imagine we have a ``Temperature`` class which samples the temperature of a

locale before reporting an average temperature. The data could come from a web

service or any other data source, but we do not have such a class at present.

We can, however, assume some basic interactions with such a class based on its

interaction with the ``Temperature`` class:

.. code-block:: php

    class Temperature

    {

        private $service;

        public function __construct($service)

        {

            $this->service = $service;

        }

        public function average()

        {

            $total = 0;

            for ($i=0; $i<3; $i++) {

                $total += $this->service->readTemp();

            }

            return $total/3;

        }

    }

Even without an actual service class, we can see how we expect it to operate.

When writing a test for the ``Temperature`` class, we can now substitute a

mock object for the real service which allows us to test the behaviour of the

``Temperature`` class without actually needing a concrete service instance.

.. code-block:: php

    use \Mockery;

    class TemperatureTest extends \PHPUnit\Framework\TestCase

    {

        public function tearDown()

        {

            Mockery::close();

        }

        public function testGetsAverageTemperatureFromThreeServiceReadings()

        {

            $service = Mockery::mock('service');

            $service->shouldReceive('readTemp')

                ->times(3)

                ->andReturn(10, 12, 14);

            $temperature = new Temperature($service);

            $this->assertEquals(12, $temperature->average());

        }

    }

We create a mock object which our ``Temperature`` class will use and set some

expectations for that mock — that it should receive three calls to the ``readTemp``

method, and these calls will return 10, 12, and 14 as results.

.. note::

    PHPUnit integration can remove the need for a ``tearDown()`` method. See

    ":doc:`/reference/phpunit_integration`" for more information.