ReferenceFileTypes

Etlunit uses a concept of reference file types which are core to how it handles data in almost every context.  Some examples of when reference file types are used:

1. The database stage operation - putting data into a database table for testing.
2. The database assertion operation - reading data from a database table and comparing to an expected data set for comparison.
3. The file assertion operation - taking a file written by a process and comparing to an expected data set for comparison.

When discussing ETL processes - especially testing - the data inputs for the test and the assertions performed on the result of the data transformation are the key features of a testing platform.  In etlunit, we take that seriously and the discussion that follows should help to fully understand the process so that your tests are well understood and stable - keys to agile unit testing and continuous integration success.