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

Transcript

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

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2. @underwaterruby
   

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3. Simone Carle4
   @weppos
   

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5. Cycle of Maintenance
   

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6. day 1
   
   

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7. year 1
   
   

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8. year 2
   
   

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9. year 3
   
   

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10. Game ver!
    

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11. the DNSimple app
    

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

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

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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
    --------------------------------------------------------------------------------
    

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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
    

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16. How can we keep our code
    maintainable?
    

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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.
    

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

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19. the DNSimple wiki
    

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

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21. Rubocop
    

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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.
    

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

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25. Code fragments
    Recurring behaviors or code fragments can
    become code snippets or be extracted.
    

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28. PaOerns are useful to
    promote code reusability
    improve long-term maintainability
    and speed up code refactoring
    

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29. 4 principles
    

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

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

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

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

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35. Measure
    Is a change really introducing quality?
    

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36. Params
    

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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
    

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38. h>ps:/
    /codeclimate.com
    

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39. Fail
    Experiments may fail!
    

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40. Beware of Mixins
    

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41. Pulling out methods from a large
    class into mixins is like hiding the
    dust under the carpet.
    

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

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

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45. Abstract
    Be in control of your code.
    

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

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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
    

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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
    

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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

    

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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

    

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51. AcKveRecord
    We have special convenHons and guidelines.
    

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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
    

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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

    

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

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57. h>p:/
    /hanamirb.org
    

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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
    

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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

    

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60. Wrapping up
    

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61. Code Monkey
    Don't be a
    

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62. Experiment
    Don't take my word for it
    

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

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

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65. Code Smells
    Pay a>enHon to
    

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66. Programming Languages
    Get influenced by other
    

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67. Start today!
    

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

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

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