Metz - Practical object-oriented design: an Agile primer using Ruby

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Meticulously pragmatic and exquisitely articulate, Practical Object Oriented Design in Ruby makes otherwise elusive knowledge available to an audience which desperately needs it. The prescriptions are appropriate both as rules for novices and as guidelines for experienced professionals.

Katrina Owen, Creator, Exercism

I do believe this will be the most important Ruby book of 2012. Not only is the book 100% on-point, Sandi has an easy writing style with lots of great analogies that drive every point home.

Avdi Grimm, author of Exceptional Ruby and Objects on Rails

While Ruby is an object-oriented language, little time is spent in the documentation on what OO truly means or how it should direct the way we build programs. Here Metz brings it to the fore, covering most of the key principles of OO development and design in an engaging, easy-to-understand manner. This is a must for any respectable Ruby bookshelf.

Peter Cooper, editor, Ruby Weekly

So good, I couldnt put it down! This is a must-read for anyone wanting to do object-oriented programming in any language, not to mention it has completely changed the way I approach testing.

Charles Max Wood, Ruby Rogues Podcast co-host and CEO of Devchat.tv

Distilling scary OO design practices with clear-cut examples and explanations makes this a book for novices and experts alike. It is well worth the study by anyone interested in OO design being done right and light. I thoroughly enjoyed this book.

Manuel Pais, DevOps and Continuous Delivery Consultant, Independent

If you call yourself a Ruby programmer, you should read this book. Its jam-packed with great nuggets of practical advice and coding techniques that you can start applying immediately in your projects.

Ylan Segal, San Diego Ruby User Group

This is the best OO book Ive ever read. Its short, sweet, but potent. It slowly moves from simple techniques to more advanced, each example improving on the last. The ideas it presents are useful not just in Ruby but in static languages like C# too. Highly recommended!

Kevin Berridge, software engineering manager, Pointe Blank Solutions, and organizer, Burning River Developers Meetup

This is the best programming book Ive read in ages. Sandi talks about basic principles, but these are things were probably still doing wrong and she shows us why and how. The book has the perfect mix of code, diagrams, and words. I cant recommend it enough and if youre serious about being a better programmer, youll read it and agree.

Derick Hitchcock, software engineer, Cisco

Metzs take on the subject is rooted strongly in theory, but the explanation always stays grounded in real world concerns, which helped me to internalize it. The book is clear and concise, yet achieves a tone that is more friendly than terse.

Alex Strasheim, network administrator, Ensemble Travel Group

Whether youre just getting started in your software development career, or youve been coding for years (like I have), its likely that youll learn a lot from Ms. Metzs book. She does a fantastic job of explaining the whys of well-designed software along with the hows.

Gabe Hollombe, software craftsman, avantbard.com

An Agile Primer Using Ruby

Second Edition

Sandi Metz

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Library of Congress Control Number: 2018939833

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ISBN-13: 978-0-13-445647-8
ISBN-10: 0-13-445647-5

For Amy, who read everything first

Introduction

We want to do our best work, and we want the work we do to have meaning. And, all else being equal, we prefer to enjoy ourselves along the way.

Those of us whose work is to write software are incredibly lucky. Building software is a guiltless pleasure because we get to use our creative energy to get things done. We have arranged our lives to have it both ways; we can enjoy the pure act of writing code in sure knowledge that the code we write has use. We produce things that matter. We are modern craftspeople, building structures that make up present-day reality, and no less than bricklayers or bridge builders, we take justifiable pride in our accomplishments.