"TDD by definition is build the test first, and then develop, which is implies, test everything." That is errant. You can create high-level tests for new funct

"TDD by definition is build the test first, and then develop, which is implies, test everything." That is errant. You can create high-level tests for new functionality, and then implement the myriad of implementation details to fulfill that test. Until all of our languages and libraries have 100% test coverage, you must decide to draw the line short somewhere. Disclaimer: I am not a TDD aficionado, and we don't practice it at the dayjob.