Refactor or Die - Speaker Deck

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REFACTOR O R D I E

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Sho Kusano @rosylilly Engineer

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http://robots.thoughtbot.com/post/50655960596/sandi-metz-rules-for-developers Sandi Metz’ rules for developers

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1 http://robots.thoughtbot.com/post/50655960596/sandi-metz-rules-for-developers Sandi Metz’ rules for developers Classes can be no longer than one hundred lines of code

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2 http://robots.thoughtbot.com/post/50655960596/sandi-metz-rules-for-developers Sandi Metz’ rules for developers Methods can be no longer than five lines of code

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3 http://robots.thoughtbot.com/post/50655960596/sandi-metz-rules-for-developers Sandi Metz’ rules for developers Pass no more than four parameters into a method. Hash options are parameters.

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4 http://robots.thoughtbot.com/post/50655960596/sandi-metz-rules-for-developers Sandi Metz’ rules for developers Controllers can instantiate only one object. Therefore, views can only know about one instance variable and views should only send messages to that object (@object.collaborator.value is not allowed)

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0 http://robots.thoughtbot.com/post/50655960596/sandi-metz-rules-for-developers Sandi Metz’ rules for developers You should break these rules only if you have a good reason or your pair lets you

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Let’s refactor your codes!

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Where we can start refactoring?

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rubocop https://github.com/bbatsov/rubocop Save your coding rules

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$ rubocop ... C:264: Surrounding space missing for '{'. C:264: Surrounding space missing for '{'. C:264: Space missing to the left of '}'. C:282: Line is too long. [98/79] C:283: Line is too long. [81/79] C:284: Method has too many lines. [45/10] C:287: Prefer single-quoted strings when you don't need string interpolation or special symbols. C:288: Line is too long. [115/79] C:298: Indent when as deep as case. C:300: Indent when as deep as case. C:305: Line is too long. [98/79] C:310: Indent when as deep as case. C:318: Indent when as deep as case. C:320: Indent when as deep as case. ...

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simplecov https://github.com/colszowka/simplecov Don’t end with “FIXME”

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$ COV=1 rspec spec/models ............................................................... Finished in 1.62 seconds 63 examples, 0 failures Coverage report generated for RSpec to coverage. 140 / 140 LOC (100.0%) covered.

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Module#deprecate http://api.rubyonrails.org/classes/Module.html#method-i-deprecate Don’t get on the time machine

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class DirtyModel def old_method # body omitted ... end deprecate :old_method def new_method # body omitted ... end if Rails.env.test? alias_method :old_method, :new_method end end

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