Progressive Admission - pattern for data processing
I don't know if there is another name for this pattern, but I've been calling it "progressive admission" and using it for many years. It is a story splitting skill, related to the "walking skelton" AKA "tracer bullet" technique. Say you are about to build a program that reads from a message queue and processes messages. Start Closed The first stage is to build the end-to-end system (reader, checker) that does nothing. No matter what you feed it, the front-end checker (correctly) reports that it's not implemented. This is beginning all closed. At this stage, you can start testing the clients and the exception handling/reporting. First Admissions Now you pick the simplest message. It could be a health message or an ill-formed message. This one message or message type is admitted . The program correctly rejects the ill-formed message, or answers the health message with a hard-coded message result. At this time, all other messages are rejected ...