When testing data transferred via an interface, what should be done?

Testing data transferred via an interface is essential to ensure data integrity and accuracy. The correct approach is to test the data both before and after the transfer. Testing before the transfer allows for the verification of the original data's validity, ensuring that it meets all requirements and is in the correct format. This initial testing is crucial as it establishes a baseline of the data quality prior to any changes or transfers.

Once the data is transferred, conducting tests again ensures that the data integrity has been maintained throughout the process. This second phase of testing helps to identify any issues that may have arisen during the transfer, such as data loss, corruption, or transformation errors. By ensuring the data is validated both before and after the transfer, you can confidently ascertain that the interface works as intended and that the data can be trusted within the new system.

In summary, this dual-phase testing—pre and post-transfer—creates a comprehensive assessment of the data handling, thereby maintaining high quality and reliability in the data being used in the system.