StatusesWebserviceTest.php

<?php
public function testStatusUpdate()
    {
        $client = $this->getMockBuilder('Cake\\Network\\Http\\Client')
            ->setMethods([
                'post'
            ])
            ->getMock();

        $client
            ->expects($this->once())
            ->method('post')
            ->with()
            ->willReturn(new Response([
                'HTTP/1.1 200 Ok'
            ], json_encode([
                'id' => 1234,
                'text' => 'Test123'
            ])));

        $this->webservice->driver()->client($client);

        $query = new Query($this->webservice, new Endpoint());
        $query->create();
        $query->set([
            'text' => 'Test123'
        ]);

        $resource = $this->webservice->execute($query);
        $this->assertInstanceOf('Muffin\\Webservice\\Model\\Resource', $resource);
        $this->assertEquals($resource->text, 'Test123');
    }