Unit Testing

Unit testing is the most common type of testing. You change individual units of work and test each change. A unit of work may be a program, a sequence of events, or just an input/output screen. However, unit testing does not test how a program interacts with other programs or its effect on the system.

Follow these steps:

Create a test stream by logging the screens connected with the change. If the program is small, you may want to log all the screens.
If you already have a test stream that tests this unit of work, you will not need to create a new one.
Change the screen in the application.
Run the logged test stream. CA Verify for VTAM compares the output produced by the program before the change with the output produced after the change.
CA Verify for VTAM flags all differences. You expect one difference — the difference in the single field, which you changed. Otherwise, the original and current screens should be the same.
If you find any unexpected differences, make corrections and rerun the logged test stream until you are sure the modified program is functioning as anticipated.