Through early morning fog I see
 visions of designs to be
 the features all withheld for me
 I realize and I can see...

 Refactoring is painless
 It brings on many changes
 and I can take or leave it if I please.

 I try to find a way to make
 all our little frobs relate
 without that ever-present bait
 but now the project isn't running late, and...

 refactoring is painless
 it brings on many changes
 and I can take or leave it if I please.
 ... and you can do the same thing if you choose.

Apologies to Johnny Mandel...

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Whew. I just worked through a major refactoring that fixed a long-standing bug in behavior of an object. It was kind of cool: every time I saw that I broke a whole bunch of tests, I backed up to the last "good" version and tried something else. The unit tests steered me into making a string of several painless changes that lead to the correct behavior! Much better than KamikazeCoding... -- MichalWallace

It's great when this happens. I think you've just reminded us of a basic tenet of refactoring - that for it to be painless you've got to have UnitTest''''''s. My problem is that I'm currently working on a code review with a company where I've recommended some major refactoring to a project. The problem is they don't have UnitTest''''''s and I have explicitly told them ''not'' to start the refactoring until they have the UnitTest''''''s. So now I have to convince their management to give them a couple of weeks in which ''no new code'' will be written so that they can write the UnitTest''''''s. ''Sigh...'' -- KyleBrown

When I am BehindOnMyTests, I write ''some'' UnitTest''''''s before refactoring. Otherwise, I have an excuse to never start refactoring. If things start breaking, I back up and write more tests. (Also, compare this page with SteveMellor's comment that ChangeShouldBePainful) -- KentBeck

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CategoryRefactoring