This post originated from an RSS feed registered with Agile Buzz by Keith Ray. Original Post: Testable Design Feed Title: MemoRanda Feed URL: http://homepage.mac.com/1/homepage404ErrorPage.html Feed Description: Keith Ray's notes to be remembered on agile software development, project management, oo programming, and other topics. Latest Agile Buzz Posts Latest Agile Buzz Posts by Keith Ray Latest Posts From MemoRanda

Roy Osherove writes (with examples) about how design improvements can make software testable. I know some readers will complain that these design changes somehow "weaken" the design, but they need to look at the bigger picture. In each example that Roy gives, the refactored (more easily testable) code has now separated concerns that were tightly-coupled. Tightly-coupled is bad.

Repeat after me: "Tightly-coupled code is bad."

Quote:

Here’s my current definition of a testable system:

"For each logical part of the system, a unit test can be written relatively easily and quickly that satisfies all the following PC-COF rules at the same time:

Partial runs are possible
Consistent results on every test run
Configuration is unneeded before run
Order of tests does not matter
Fast run time"