_objectManagerMock = $this->createMock(\Magento\Framework\ObjectManagerInterface::class); $this->_model = new \Magento\Framework\EventFactory($this->_objectManagerMock); $this->_expectedObject = $this->getMockBuilder(\Magento\Framework\Event::class)->getMock(); } public function testCreate() { $arguments = ['property' => 'value']; $this->_objectManagerMock->expects( $this->once() )->method( 'create' )->with( \Magento\Framework\Event::class, $arguments )->will( $this->returnValue($this->_expectedObject) ); $this->assertEquals($this->_expectedObject, $this->_model->create($arguments)); } }