registryMock = $this->createMock(\Magento\Framework\Registry::class); $this->collectionUpdater = new \Magento\Sales\Model\Grid\Child\CollectionUpdater( $this->registryMock ); } public function testUpdateIfOrderExists() { $collectionMock = $this->createMock( \Magento\Sales\Model\ResourceModel\Order\Payment\Transaction\Collection::class ); $transactionMock = $this->createMock(\Magento\Sales\Model\Order\Payment\Transaction::class); $this->registryMock ->expects($this->once()) ->method('registry') ->with('current_transaction') ->will($this->returnValue($transactionMock)); $transactionMock->expects($this->once())->method('getId')->will($this->returnValue('transactionId')); $collectionMock->expects($this->once())->method('addParentIdFilter')->will($this->returnSelf()); $this->assertEquals($collectionMock, $this->collectionUpdater->update($collectionMock)); } }