Maintaining a 6yo Ruby Project (RubyConf.PH 2016)

Transcript

1. Maintaining a 6yo Project Simone Carle, / / DNSimple

2. @underwaterruby

3. Simone Carle4 @weppos

4. None

5. Cycle of Maintenance

6. day 1

7. year 1

8. year 2

9. year 3

10. Game ver!

11. the DNSimple app

12. How big is it? It's hard to find reasonable code

    metrics

13. Lines of code are useful only when bragging to project

    managers.

14. ➜ dnsimple git:(master) cloc . 4366 text files. 4357 unique

    files. 1174 files ignored. https://github.com/AlDanial/cloc v 1.66 T=22.99 s (139.3 files/s, 8110.2 lines/s) -------------------------------------------------------------------------------- Language files blank comment code -------------------------------------------------------------------------------- Ruby 2484 26061 5974 93289 JavaScript 18 3151 2460 15161 ERB 479 2187 0 14462 SASS 46 618 153 4253 SQL 4 2903 2685 4253 CoffeeScript 86 938 190 3043 XML 17 1 0 1918 JSON 46 32 0 1088 YAML 11 122 260 509 CSS 3 11 0 309 HTML 7 48 0 263 Bourne Again Shell 1 13 0 63 -------------------------------------------------------------------------------- SUM: 3202 36085 11722 138611 --------------------------------------------------------------------------------

15. +----------------------+-------+-------+---------+---------+-----+-------+ | Name | Lines | LOC | Classes |

    Methods | M/C | LOC/M | +----------------------+-------+-------+---------+---------+-----+-------+ | Controllers | 6481 | 4833 | 123 | 738 | 6 | 4 | | Helpers | 1825 | 1216 | 10 | 202 | 20 | 4 | | Models | 9540 | 6138 | 147 | 966 | 6 | 4 | | Mailers | 390 | 274 | 11 | 41 | 3 | 4 | | Javascripts | 2419 | 1850 | 36 | 490 | 13 | 1 | | Libraries | 14452 | 9877 | 340 | 1465 | 4 | 4 | | Api specs | 3519 | 2634 | 0 | 3 | 0 | 876 | | Clock specs | 19 | 14 | 0 | 0 | 0 | 0 | | Command specs | 8084 | 6066 | 3 | 4 | 1 | 1514 | | Controller specs | 10261 | 7710 | 0 | 1 | 0 | 7708 | | Feature specs | 143 | 109 | 0 | 3 | 0 | 34 | | Finder specs | 3873 | 2918 | 0 | 11 | 0 | 263 | | Helper specs | 1943 | 1502 | 2 | 1 | 0 | 1500 | | Integration specs | 32 | 25 | 0 | 0 | 0 | 0 | | Lib specs | 13906 | 10769 | 2 | 35 | 17 | 305 | | Mailer specs | 720 | 560 | 0 | 0 | 0 | 0 | | Model specs | 14719 | 11441 | 0 | 18 | 0 | 633 | | Processor specs | 1354 | 1074 | 0 | 0 | 0 | 0 | | Request specs | 5101 | 3843 | 0 | 6 | 0 | 638 | | Routing specs | 6088 | 4890 | 0 | 0 | 0 | 0 | | Serializer specs | 576 | 460 | 0 | 0 | 0 | 0 | | Validator specs | 609 | 476 | 6 | 9 | 1 | 50 | | Worker specs | 1320 | 941 | 0 | 0 | 0 | 0 | +----------------------+-------+-------+---------+---------+-----+-------+ | Total | 107374 | 79620 | 680 | 3993 | 5 | 17 | +----------------------+-------+-------+---------+---------+-----+-------+ Code LOC: 24188 Test LOC: 55432 Code to Test Ratio: 1:2.3

16. How can we keep our code maintainable?

17. convention |kənˈvɛnʃ(ə)n| 1 a way in which something is usually

    done: to attract the best patrons the movie houses had to ape the conventions and the standards of theatres. • [ mass noun ] behaviour that is considered acceptable or polite to most members of a society: he was an upholder of convention and correct form | [ count noun ] : the law is felt to express social conventions. 2 an agreement between states covering particular matters, especially one less formal than a treaty. the convention, signed by the six states bordering on the Black Sea, aims to prevent further pollution.

18. ConvenKons are important to ensure that the enKre team speaks

    the same language

19. the DNSimple wiki

20. the GitHub Ruby style guide h>ps:/ /github.com/styleguide/ruby the Ruby Style

    Guide h>ps:/ /github.com/bbatsov/ruby-style-guide

21. Rubocop

22. pattern |ˈpat(ə)n| 2 a regular and intelligible form or sequence

    discernible in the way in which something happens or is done: a complicating factor is the change in working patterns. 4 an excellent example for others to follow: he set the pattern for subsequent study.

23. Text paOerns Homogeneous text and names are easier to search

    and refactor.
24. None

25. Code fragments Recurring behaviors or code fragments can become code

    snippets or be extracted.
26. None
27. None

28. PaOerns are useful to promote code reusability improve long-term maintainability

    and speed up code refactoring

29. 4 principles

30. Experiment SomeHmes the code is not ready for extracHon.

31. Stand out When you experiment, write code that the team

    will noHce.

32. Bonus point: __ is also easy to grep!

33. "Stupid Names" Catch the a>enHon of the other developers.

34. None

35. Measure Is a change really introducing quality?

36. Params

37. class ContactParams
 include ParamsAllowed
 
 def self.allowed
 [:label, :first_name, :last_name,

    :address, :city, :state, :postal_code, :country, :email, :phone]
 end
 end
 
 
 # Params encapsulate the logic to handle some parameters from an untrusted source.
 #
 # A Params object generally doesn't include the Param module directly. Instead, it relies to one of the
 # more specific implementations, such as ParamsAllowed.
 module Params
 def initialize(params)
 @params = ActiveSupport::HashWithIndifferentAccess.new(params.to_h)
 end
 end
 
 
 module ParamsAllowed
 def self.included(base)
 base.include Params
 end
 
 def to_h
 @params.slice(*self.class.allowed).to_hash.symbolize_keys!
 end
 end

38. h>ps:/ /codeclimate.com

39. Fail Experiments may fail!

40. Beware of Mixins

41. Pulling out methods from a large class into mixins is

    like hiding the dust under the carpet.
42. None

43. – Anonymous "Any application with an app/concerns directory is concerning."

44. We're not afraid to be mistaken and learn from failed

    experiments.

45. Abstract Be in control of your code.

46. Custom API Any external dependency we introduce, we wrap it

    behind a custom API.

47. require 'phony'
 
 module Dnsimple
 
 # Phone is a

    wrapper for the current phone validation library.
 module Phone
 
 WHITELIST = {
 "+3912312345678" => "+39 12312345678"
 }
 
 # Makes a plausibility check on the number.
 def self.plausible?(number)
 whitelisted?(number) || 
 Phony.plausible?(number)
 end
 
 def self.format(number)
 whitelisted?(number) || 
 Phony.formatted(Phony.normalize(number), parentheses: false)
 end

48. • Side features or extensions can be introduced without an

    extensive change to the codebase • IncompaHbiliHes can be addressed in a single place • When and if needed, the external dependency can be replaced with li>le effort • TesHng doesn't require intensive stubbing

49. module Dnsimple
 class AliasResolver
 
 class << self
 def adapter


    @adapter ||= NullAdapter.new
 end
 
 def resolve(name)
 adapter.resolve(name)
 end
 
 def enable_test!
 self.adapter = test_adapter.new
 end
 end
 # NullAdapter is a special adapter
 # that discards every resolve request.
 class NullAdapter
 def resolve(name)
 Result.new(name, [], [])
 end
 end
 
 class TestAdapter
 def resolve(*)
 result = @stubs.shift
 result ? Result.new(*result) : Result.new
 end
 end
 
 class GoAdapter
 BIN = File.join(Rails.root, "bin", "dsalias")
 
 def resolve(name)
 #
 end
 end


50. Dnsimple::AliasResolver.enable_test!
 
 describe "a methods that interacts with the resolver"

    do
 before do
 AliasResolver.adapter.test :stub, "fully.qualified.host"
 end
 
 it "does something" do
 # ...
 end
 end


51. AcKveRecord We have special convenHons and guidelines.

52. • Methods defined in ActiveRecord::Base are not allowed outside the

    Models • Models MUST expose custom API to perform operaHons • Callbacks are allowed only for data integrity • Query methods in ActiveRecord::Base are not allowed outside the Models or Finders • Scopes can't be invoked directly outside Models or Finders and they exist only to support Finders

53. require 'model_finder'
 
 class SuffixFinder
 include ModelFinder::Finder
 
 def self.find(identifier)


    find_by_tld(identifier)
 end
 
 def self.find!(identifier)
 find(identifier) or not_found!(identifier)
 end
 
 def self.find_by_tld(identifier)
 tld = identifier.to_s.downcase
 enabled.where(tld: tld).take
 end
 
 def self.suffix_listing
 scope.enabled
 end
 def self.newgtld_suffixes
 scope.new_tlds.enabled.order_alpha
 end
 
 def self.gtld_suffixes
 scope.global_tlds.enabled.order_alpha
 end
 
 def self.cctld_suffixes
 scope.cc_tlds.enabled.order_alpha
 end
 
 def self.privacy_supported_tlds
 scope.where(whois_privacy: true).pluck(:tld)
 end
 
 private
 
 def self.not_found!(identifier)
 raise(ActiveRecord::RecordNotFound, "TLD `#{identifier}` not found")
 end
 
 end


54. These guidelines are the result of years of experiments, discussions

    and refactoring.
55. None
56. None

57. h>p:/ /hanamirb.org

58. module Controllers::Domains
 class Create
 def call(params)
 @result = DomainCreateCommand.execute(
 command_context,

    
 this_account, 
 DomainParams.new(params))
 @domain = @result.data
 
 if @result.successful?
 render DomainSerializer.new(@domain), 201
 else
 render ErrorSerializer.new(@result.error, @domain) end
 end
 end
 end class DomainHostingController
 def create
 @result = DomainCreateCommand.execute(
 command_context,
 this_account,
 domain_params)
 @domain = @result.data
 
 if @result.successful?
 redirect_to domain_path(@domain)
 else
 format.html { render action: "new" }
 end
 end
 end

59. module Api::V2
 module Controllers::RegistrarWhoisPrivacy
 
 class Enable
 include Hanami::Action
 before

    :require_subscription!, :require_good_standing!
 
 def call(params)
 # code
 end
 end
 
 class Disable
 include Hanami::Action
 before :require_subscription!
 
 def call(params)
 # code
 end
 end
 
 end
 end


60. Wrapping up

61. Code Monkey Don't be a

62. Experiment Don't take my word for it

63. Fail It's ok. Be ready to fail and learn from

    failures.

64. Small steps Don't throw away your enHre codebase

65. Code Smells Pay a>enHon to

66. Programming Languages Get influenced by other

67. Start today!

68. Credits • h>ps:/ /www.flickr.com/photos/goya74/8584790873 • h>ps:/ /www.flickr.com/photos/81723459@N04/22559333751/

69. Thanks! DNSimple dnsimple.com @dnsimple Simone Carle4 simonecarle4.com @weppos