The question I ask myself is "If X changes, how many places in the code need to change?", for any reasonable value of X. If the answer is 2 or more, you probab

The question I ask myself is "If X changes, how many places in the code need to change?", for any reasonable value of X. If the answer is 2 or more, you probably want to deduplicate something. If not, it doesn't really matter if different code looks similar.