Blog
Mert Özen's blog posts on software development, backend, frontend, and DevOps.
What Is TDD? Canon TDD, the Test List and the Real Purpose of Red-Green-Refactor
TDD is not writing lots of unit tests but a discipline of growing behavior in small steps while correcting the design all the time: a test list first, then one test from it, red, green, an optional refactor and an updated list. We look at Kent Beck's Canon TDD, how it differs from Uncle Bob's three laws, and how the list for Bookstore's CouponValidator changes over two loops, with real test output.
Red-Green-Refactor in Practice: Fake It, Triangulation, Obvious Implementation and Baby Steps
There are three ways to turn a red test green: obvious implementation when you know the code, fake it when you don't, triangulation when the design is unclear; and every surprising red means a smaller step. Growing CouponValidator live with xUnit v3, we see a banker's rounding surprise, a fake that breaks old tests, verifying a test that was green right away by breaking the code, an Istanbul-time expiry rule with TimeProvider and a small commit on every green, with real output.