Why do we need proper unit testing? Generally, at least 60% of an IBM i application is made up of ‘batch’ processes; processes without a User Interface. Information enters and leaves the system as messages on data queues and MQ Queues, as well as through a User Interface. This makes a large portion of the application a ‘black box’. As a developer you can resort to using debug techniques to see what is going on, but these are slow to use and laborious to set-up.
What you really need is a test-harness – a proper unit testing tool that will enable you to test components in isolation and provide diagnostic feedback as to what those components are doing; passing and receiving parameter values, reading from and writing to a queue, updating data in the database as well as triggering down-stream processes, and knowing what those triggered processes are doing.