Best Practices for ETL Testing

1. Make sure data is transformed correctly
2.  Without any data loss and truncation projected data should be loaded into the data warehouse
3.  Ensure that ETL application appropriately rejects and replaces with default values and reports invalid data
4.  Need to ensure that the data loaded in data warehouse within prescribed and expected time frames to confirm scalability and performance
5.  All methods should have appropriate unit tests regardless of visibility
6. To measure their effectiveness all unit tests should use appropriate coverage techniques
7. Strive for one assertion per test case
8.  Create unit tests that target exceptions