I don't think we disagree. It's just that a lambda doesn't change this. If the lambda itself also contains a branch, then yeah, you should probably test the outer function with at least 2 inputs.
I agree, except I think that a lamdba is an arbitrary line to draw for that as well. Why not stop at the main function and give it a load of inputs? A five line lamdba looks a lot like a named function, just harder to test, reuse, and debug in a stack trace.
> 20 short functions definitely sound as though they should be explicit.
And you are right that it's pretty arbitrary when/if a lambda should specifically be tested or not. But the number of lambdas in a project isn't really a good factor to make that decision - it's individual for each function that contains a lambda.
Well, I more meant that if they're "short" as opposed to "20 character one-liners" then it sounds as though they should be tested, whether or not they're defined using lambda syntax.
