I personally factorize as soon as there are two copies, but do not hesitate to inline the code and redo the abstraction when there is a 3rd use if it doesn’t fit. I find it much easier to inline and re-abstact a bad abstraction, than check if two copies are indeed identical.
The exception is business logic. Usually I want all of them to be dupplicates because there is a very high chance that it’s just accidental that part of the logic is similar. I take great care to have good primitives but the actual business logic that glue those primitives together is written as many time as needed.
I personally factorize as soon as there are two copies, but do not hesitate to inline the code and redo the abstraction when there is a 3rd use if it doesn’t fit. I find it much easier to inline and re-abstact a bad abstraction, than check if two copies are indeed identical.
The exception is business logic. Usually I want all of them to be dupplicates because there is a very high chance that it’s just accidental that part of the logic is similar. I take great care to have good primitives but the actual business logic that glue those primitives together is written as many time as needed.