<aside> <img src="/icons/info-alternate_blue.svg" alt="/icons/info-alternate_blue.svg" width="40px" /> Tidying up messy software is a must. And that means breaking up the code to make it more readable, and using guard clauses and helping functions to make it understandable. In this practical guide, author Kent Beck, creator of Extreme Programming and pioneer of software patterns, suggests when and where you might apply tidyings in your code

Instead of trying to master tidying all at once, this book lets you try out a few examples that make sense for your problem. If you have a big function containing many lines of code, you'll learn how to logically divide it into smaller chunks. Along the way, you'll learn the theory behind software design: coupling, cohesion, discounted cash flows, and optionality.

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What is Tidy First?

“I have to change this code but it’s messy. What should I do next?”

Tidy First? is the next step in my mission to help geeks feel safe in the world. It’s also the first step to take when addressing the common question posed above. Software design is a powerful tool to ease pain in the world—if it is used well. Used badly, it becomes just another instrument of oppression and becomes a drag on the effectiveness of software development.

A tidying is a teensy-weensy, cute, fuzzy, little refactoring. It’s a change to the structure that will make it easier to change the behavior. This tidy-first work helps to make changing the structure of code not intimidating.

What You Will Learn

By the end of this book, you will understand:

• The fundamental difference between changes to the behavior of a system & changes to its structure.
• The enabling magic of alternating investment in structure & investment in behavior, as a lone programmer changing code.
• The basics of the theory of how software design works & the forces that act on it.

And you will be able to:

• Improve your own experience of programming by sometimes tidying first (and sometimes tidy after).
• Begin to make large changes in small, safe steps.
• Prepare to design as a human activity with diverging incentives.

intellectual puzzle.

Part I. Introduction

The author is writing about software design because they believe it's a powerful tool often misused or misunderstood. Their primary motivation stems from a personal mission to "help geeks feel safe in the world," which in this context means helping software developers design software in ways that are less likely to cause errors or strain team relationships.

The author emphasizes:

• Safe, small steps: Advocating for incremental changes and continuous improvement rather than large, risky overhauls.
• The importance of "how much?" and "when?": Criticizing other design discussions for neglecting the practical considerations of timing and the extent of design effort.