Say I have a class with a single constructor that accepts 2 parameters and initialises itself using those parameters. I have written tests for this and they are all passing.
I later realise I need to make an addition to the constructor to accept three parameters. Should I
a) Add in the new parameter, watch my tests break and try and fix it
b) Rewrite existing tests to test for the new expected behavior, watch them initially fail and then add to the class (this to me seems a more TDD way)
From a TDD point of view, I think that option 'b' makes more sense. However, option 'a' (to me) seems like a more natural approach.
Is there any standard way that most people do this?