Harry Potter and The Legacy Codebase

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Harry Potter and The Legacy Codebase 1 Friday, February 21, 14

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Harry Potter and The Legacy Codebase 2 Friday, February 21, 14

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MINSWAN 4 Friday, February 21, 14

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NIRD.us 5 Friday, February 21, 14

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AdaDevelopersAcademy.org 6 Friday, February 21, 14

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WHY YOU’RE HERE • House New Hire -- You’re a new developer joining an established team • House Reorg -- Hogwarts-Online reorg assigned this to you • House Feddup -- You’ve decided you’ve had enough and volunteered 9 Friday, February 21, 14

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LEGACY CODE ISN’T EVIL, IT’S JUST MISUNDERSTOOD 11 Friday, February 21, 14

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IDEAL HABITAT • Software that has been superseded but is difﬁcult to replace because everyone and everything relies on it • Code without tests • Code that you didn’t write • Code written before today 12 Friday, February 21, 14

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CODE ARCHEOLOGY 101 15 Friday, February 21, 14

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CODE ARCHEOLOGY 101 • Achieve a better understanding of the overall architecture • Discover the root cause of a critical bug • Determine the best way to extend the functionality of a vestigial class • Investigate a previous approach to solving a current problem In this class you will learn how to... 17 Friday, February 21, 14

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CODE ARCHEOLOGY 101 •Surveyance •Excavation •Analysis Each House will complete one of three tasks... 18 Friday, February 21, 14

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BE BRAVE 19 Friday, February 21, 14

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TO FALLEN COMRADES 20 Friday, February 21, 14

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SURVEYANCE 23 Friday, February 21, 14

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TAKE INVENTORY 24 Friday, February 21, 14

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ASK DUMB QUESTIONS 25 Friday, February 21, 14

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FLAG MYTHS 26 Friday, February 21, 14

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Tricks ↓ Techniques ↓ Process ↓ Methodology ↓ Dogma 27 Friday, February 21, 14

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class Basilisk < ActiveRecord::Base def remove_poison update!(ink_quantity: 0) end end 28 Friday, February 21, 14

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class PoisonBarrel < ActiveRecord::Base def self.first_free_barrel(liters_needed) free = DEFAULT_CAPACITY - liters_needed InkBarrel.where("liters < ?", free) end def self.with_free_space(liters_needed) if self.first_free_barrel(liters_needed) return barrels.first else return PoisonBarrel.create! end end end 29 Friday, February 21, 14

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class Basilisk < ActiveRecord::Base def remove_poison barrel = PoisonBarrel. with_free_space(poison_quantity) barrel.liters += poison_quantity barrel.save! update!(ink_quantity: 0) end end 30 Friday, February 21, 14

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EXCAVATION 31 Friday, February 21, 14

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"FIRST, DO NO HARM" 33 Friday, February 21, 14

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class Basilisk < ActiveRecord::Base def remove_poison warn "#remove_poison has been deprecated. “ + “Use #harvest_poison instead." harvest_poison end def harvest_poison store_poison_in(poison_container, poison_quantity) update!(poison_quantity: 0) end private def store_poison_in(container, poison_quantity) container.first_with_free_space(poison_quantity). update!(liters: poison_quantity) end end 34 Friday, February 21, 14

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ANALYSIS / DOCUMENTATION 35 Friday, February 21, 14

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DOCUMENT EVERYTHING 36 Friday, February 21, 14

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MAKE A MAP 37 Friday, February 21, 14

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FINAL EXAMS 38 Friday, February 21, 14

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★ glass artist ★ Vespa mechanic ★ lighting designer ★ author & teacher ★ player of games ★ software developer @kerrizor KERRI MILLER 40 Friday, February 21, 14

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