[victorNicollet]

I share their opinion. I understand "Do the simplest thing" to mean "ignore any additional insights you may have".

If I know that a class will need to be accessed from multiple threads, I am not allowed to use locks, concurrent data structures or lock-free patterns until I add the first test that checks for multiple thread access. When that happens, I need to throw away almost all of the previous implementation. The same happens for any special data structure or algorithm that I know in advance will be necessary to solve the high-level problem, but it takes tens of tests to reach a point where the "simplest solution" no longer works. As an exercise, consider implementing a Union-Find data structure while constraining yourself to never writing a line of code that is not the simplest thing to solve the current test.

My experience has been that it's better in those cases to construct a unit testing roadmap so that:

- you incrementally build the correct solution - you throw away as little code as possible - throughout the process, you minimize the amount of code not covered by a test

[pjc50]

> If I know that a class will need to be accessed from multiple threads, I am not allowed to use locks, concurrent data structures or lock-free patterns until I add the first test that checks for multiple thread access. When that happens, I need to throw away almost all of the previous implementation. The same happens for any special data structure or algorithm that I know in advance will be necessary to solve the high-level problem, but it takes tens of tests to reach a point where the "simplest solution" no longer works. As an exercise, consider implementing a Union-Find data structure while constraining yourself to never writing a line of code that is not the simplest thing to solve the current test.

Who's imposing that constraint on you? Why? Can't you negotiate your way out of that?

[rolisz]

TDD. That's the point of TDD and that's what people are arguing against. If you relax this constraint, you get something different.

[ncann]

I share the same sentiment. TDD is one of those things that are really nice on paper for trivial toy code like Cat extends Animal, but quickly becomes impractical and falls apart against real world problems.