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+++
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title = "Things I Learnt The Hard Way - Be Ready To Throw Your Code Away"
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date = 2019-06-19
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[taxonomies]
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tags = ["en-au", "book", "things i learnt", "code"]
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+++
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A lot of people, when they start with TDD, get annoyed when you say that you
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may have to rewrite a lot of stuff, including whatever your already wrote.
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<!-- more -->
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TDD was _designed_ to throw code away: The more you learn about your problem,
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the more you understand that, whatever you wrote, won't solve the problem in
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the long run. Also, as you slowly solve new problems, you may notice some
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pattern in the code emerging (you're doing the same thing over and over, with
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only minor changes). That's a good time to go over and rewrite everything to
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take advantage of this pattern.
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You shouldn't worry about this. Your code is not a wall (or any physical
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object): if you have to throw it away, you didn't wasted materials. Surely it
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means your time writing code was lost, but you got a better understanding
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about the problem now, or you may start to think in a more concise way to
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solve the problem.
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Not only that, but as you progress through your project, solving problems and
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getting "acquainted" with the problem, you'll also notice that the
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[spec](/books/things-i-learnt/spec-first) will also change. This means that
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the problem your code solve wasn't exactly the problem you _needed_ to solve;
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your code is trying to solve something that isn't exactly the problem.
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Also, specs changing is really common. One thing that you can be sure is that
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it won't change _everywhere_. Some of the things you solved will stay the
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same, some others will be completely removed and some others added. And you
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will see that you'll refactor your code a lot, and throw a lot of code away.
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And not just code that solves the problem, but also the tests for that code.
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... unless you focus mostly on [integration
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tests](/books/things-i-learnt/integration-tests).
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{{ chapters(prev_chapter_link="/books/things-i-learnt/config-file", prev_chapter_title="The Config File Is Friend", next_chapter_link="/books/things-i-learnt/future-trashing", next_chapter_title="Future Thinking Is Future Trashing") }}
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