public function testSave() { $entity = $this->getMockBuilder('Magento\\Sales\\Model\\Order\\Invoice')->disableOriginalConstructor()->getMock(); $entity->expects($this->any())->method('getEntityId')->willReturn(1); $mapper = $this->getMockBuilder('Magento\\Sales\\Model\\ResourceModel\\Order\\Invoice')->disableOriginalConstructor()->getMock(); $mapper->expects($this->once())->method('save')->with($entity); $this->invoiceMetadata->expects($this->any())->method('getMapper')->willReturn($mapper); $this->assertEquals($entity, $this->invoice->save($entity)); }