public function testAroundExecute() { $subjectMock = $this->getMock('Magento\Framework\App\Action\Action', [], [], '', false); $designLoaderMock = $this->getMock('Magento\Framework\View\DesignLoader', [], [], '', false); $closureMock = function () { return 'Expected'; }; $requestMock = $this->getMock('Magento\Framework\App\RequestInterface'); $plugin = new \Magento\Framework\App\Action\Plugin\Design($designLoaderMock); $designLoaderMock->expects($this->once())->method('load'); $this->assertEquals('Expected', $plugin->aroundExecute($subjectMock, $closureMock, $requestMock)); }