IMNSHO, the norm in the ruby community as of late as not been refactor, but rewrite.
When the rails folk redesign the route system it's not a refactoring cause a refactoring keeps functionalities unchanged, it does not add/remove/change corner cases. Which has happened in all major rails releases and some point ones.
It wasn't a rewrite. The point of TDD-assisted refactoring isn't to not change anything ever, it's to change things in a controlled way and prevent regressions. It was actually pretty interesting to watch carlhuda and the rails team take rails from 2.3 to 3.0.
That simply isn't true. I'd urge you to pick up a copy of Fowler's "Refactoring: Improving the Design of Existing Code."
"Refactoring" as a term was defined in that book. It has very much been diluted into "I changed some code because I think this is better," which is a shame because it has a very clear definition.
I should also note that having a test suite allows you to refactor with more confidence, but it's neither a requirement nor changes the definition at all. So a "TDD-assisted refactoring" isn't different from a "refactoring."
When the rails folk redesign the route system it's not a refactoring cause a refactoring keeps functionalities unchanged, it does not add/remove/change corner cases. Which has happened in all major rails releases and some point ones.