Code diving in Ruby and Rails

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Code Diving inRuby Evan Dorn Founder, Logical Reality Design http://lrdesign.com evan@lrdesign.com @idahoev Friday, August 9, 13

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SO YOU’RE CODING ALONGWHEN... Friday, August 9, 13

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1) InvoicesController asan admin GET index should paginate all unpaid invoices as @unpaid_invoices Failure/Error: get :index NoMethodError: undefined method `unpayed' for #<Class:0x007fd8cfe9ee18> # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activerecord-3.2.12/lib/active_record/dynamic_matchers.rb:55:in `method_missing' # ./app/controllers/invoices_controller.rb:7:in `index' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ actionpack-3.2.12/lib/action_controller/metal/implicit_render.rb:4:in `send_action' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ actionpack-3.2.12/lib/abstract_controller/base.rb:167:in `process_action' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ actionpack-3.2.12/lib/action_controller/metal/rendering.rb:10:in `process_action' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ actionpack-3.2.12/lib/abstract_controller/callbacks.rb:18:in `block in process_action' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activesupport-3.2.12/lib/active_support/callbacks.rb:447:in `_run__3859364058582123788__process_action__4176185741589430016__callbacks' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activesupport-3.2.12/lib/active_support/callbacks.rb:405:in `__run_callback' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activesupport-3.2.12/lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activesupport-3.2.12/lib/active_support/callbacks.rb:81:in `run_callbacks' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ actionpack-3.2.12/lib/abstract_controller/callbacks.rb:17:in `process_action' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ actionpack-3.2.12/lib/action_controller/metal/rescue.rb:29:in `process_action' # /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ actionpack-3.2.12/lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' Friday, August 9, 13

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AND YOU’RE LIKE Friday,August 9, 13

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BUT THEN YOUNOTICE THIS... Friday, August 9, 13

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BUT WHAT ABOUT WHEN... Friday,August 9, 13

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/Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/active_support/ core_ext/hash/keys.rb:25:in `symbolize_keys': Youblew it, dumbass (RuntimeError) from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activerecord-3.2.12/lib/ active_record/connection_adapters/abstract/connection_specification.rb:45:in `resolve_hash_connection' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activerecord-3.2.12/lib/ active_record/connection_adapters/abstract/connection_specification.rb:41:in `resolve_string_connection' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activerecord-3.2.12/lib/ active_record/connection_adapters/abstract/connection_specification.rb:25:in `spec' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activerecord-3.2.12/lib/ active_record/connection_adapters/abstract/connection_specification.rb:130:in èstablish_connection' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activerecord-3.2.12/lib/ active_record/railtie.rb:82:in `block (2 levels) in <class:Railtie>' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/ active_support/lazy_load_hooks.rb:36:in ìnstance_eval' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/ active_support/lazy_load_hooks.rb:36:in èxecute_hook' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/ active_support/lazy_load_hooks.rb:26:in `block in on_load' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/ active_support/lazy_load_hooks.rb:25:in èach' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/ active_support/lazy_load_hooks.rb:25:in òn_load' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activerecord-3.2.12/lib/ active_record/railtie.rb:74:in `block in <class:Railtie>' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/railties-3.2.12/lib/rails/ initializable.rb:30:in ìnstance_exec' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/railties-3.2.12/lib/rails/ initializable.rb:30:in `run' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/railties-3.2.12/lib/rails/ initializable.rb:55:in `block in run_initializers' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/railties-3.2.12/lib/rails/ initializable.rb:54:in èach' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/railties-3.2.12/lib/rails/ initializable.rb:54:in `run_initializers' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/railties-3.2.12/lib/rails/ application.rb:136:in ìnitialize!' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/railties-3.2.12/lib/rails/ railtie/configurable.rb:30:in `method_missing' from /Volumes/Valinor/Users/evan/Development/Ruby/apps/tracks/config/environment.rb:5:in `<top (required)>' from /Volumes/Valinor/Users/evan/Development/Ruby/apps/tracks/spec/spec_helper.rb:3:in `require' from /Volumes/Valinor/Users/evan/Development/Ruby/apps/tracks/spec/spec_helper.rb:3:in `<top Friday, August 9, 13

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IT’S PROBABLY SOMETHING YOUDID. Friday, August 9, 13

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IT’S PROBABLY SOMETHING YOUDID. (but the error’s not in your code) Friday, August 9, 13

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RAILS’ CODE IS HARDTO UNDERSTAND Friday, August 9, 13

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RAILS’ CODE IS HARDTO UNDERSTAND But that doesn’t matter! Dive in anyway. Friday, August 9, 13

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RUBY IS ARUN-TIME LANGUAGE Friday, August 9, 13

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RUBY IS ARUN-TIME LANGUAGE •This makes it hard to ﬁnd stuff! Friday, August 9, 13

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RUBY IS ARUN-TIME LANGUAGE •This makes it hard to ﬁnd stuff! •Your IDE isn’t much help Friday, August 9, 13

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RUBY IS ARUN-TIME LANGUAGE •This makes it hard to ﬁnd stuff! •Your IDE isn’t much help •So ﬁnd stuff AT RUN TIME Friday, August 9, 13

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JUST OPEN THATFILE Friday, August 9, 13

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JUST OPEN THATFILE Don’t be intimidated ... it’s all just Ruby Friday, August 9, 13

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JUST OPEN THATFILE ~/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/active_support/ core_ext/hash/keys.rb:25:in `symbolize_keys': You blew it, dumbass (RuntimeError) from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activerecord-3.2.12/lib/active_record/connection_adapters/abstract/ connection_specification.rb:45:in `resolve_hash_connection' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activerecord-3.2.12/lib/active_record/connection_adapters/abstract/ connection_specification.rb:41:in `resolve_string_connection' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ Don’t be intimidated ... it’s all just Ruby Friday, August 9, 13

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JUST OPEN THATFILE ~/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12/lib/active_support/ core_ext/hash/keys.rb:25:in `symbolize_keys': You blew it, dumbass (RuntimeError) from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activerecord-3.2.12/lib/active_record/connection_adapters/abstract/ connection_specification.rb:45:in `resolve_hash_connection' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ activerecord-3.2.12/lib/active_record/connection_adapters/abstract/ connection_specification.rb:41:in `resolve_string_connection' from /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ $ vim ~evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/activesupport-3.2.12 Don’t be intimidated ... it’s all just Ruby Friday, August 9, 13

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USE GEM... Friday, August9, 13

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USE GEM... $ gemenv Friday, August 9, 13

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USE GEM... RubyGems Environment: -RUBYGEMS VERSION: 1.8.25 - RUBY VERSION: 1.9.3 (2012-11-10 patchlevel 327) [x86_64-darwin11.4.2] - INSTALLATION DIRECTORY: /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fas - RUBY EXECUTABLE: /Volumes/Valinor/Users/evan/.rvm/rubies/ruby-1.9.3-p327-fast/bin/ - EXECUTABLE DIRECTORY: /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327- fast@tracks/bin - RUBYGEMS PLATFORMS: - ruby - x86_64-darwin-11 - GEM PATHS: - /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks - /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@global - GEM CONFIGURATION: $ gem env Friday, August 9, 13

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USE GEM... RubyGems Environment: -RUBYGEMS VERSION: 1.8.25 - RUBY VERSION: 1.9.3 (2012-11-10 patchlevel 327) [x86_64-darwin11.4.2] - INSTALLATION DIRECTORY: /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fas - RUBY EXECUTABLE: /Volumes/Valinor/Users/evan/.rvm/rubies/ruby-1.9.3-p327-fast/bin/ - EXECUTABLE DIRECTORY: /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327- fast@tracks/bin - RUBYGEMS PLATFORMS: - ruby - x86_64-darwin-11 - GEM PATHS: - /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks - /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@global - GEM CONFIGURATION: $ gem env Friday, August 9, 13

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USE GEM... RubyGems Environment: -RUBYGEMS VERSION: 1.8.25 - RUBY VERSION: 1.9.3 (2012-11-10 patchlevel 327) [x86_64-darwin11.4.2] - INSTALLATION DIRECTORY: /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fas - RUBY EXECUTABLE: /Volumes/Valinor/Users/evan/.rvm/rubies/ruby-1.9.3-p327-fast/bin/ - EXECUTABLE DIRECTORY: /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327- fast@tracks/bin - RUBYGEMS PLATFORMS: - ruby - x86_64-darwin-11 - GEM PATHS: - /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks - /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@global - GEM CONFIGURATION: $ gem env $ cd /Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks Friday, August 9, 13

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ASK RUBY YOUR QUESTIONS! Friday,August 9, 13

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WHAT’S THIS VALUE? #activesupport-3.2.12/lib/active_support/core_ext/hash classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you use strings for keys but assert symbols Friday, August 9, 13

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WHAT’S THIS VALUE? #activesupport-3.2.12/lib/active_support/core_ext/hash classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you use strings for keys but assert symbols Friday, August 9, 13

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WHAT’S THIS VALUE? #activesupport-3.2.12/lib/active_support/core_ext/hash classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys p self dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you Friday, August 9, 13

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TOO MUCH OUTPUT! .{:client_id=>"24"} {"controller"=>"invoices","action"=>"new"} .{:client_id=>"27"} {"controller"=>"invoices", "action"=>"new"} .{:client_id=>"30"} {"controller"=>"invoices", "action"=>"new"} .{:client_id=>"33"} {"controller"=>"invoices", "action"=>"new"} .{:client_id=>"37"} {"controller"=>"invoices", "action"=>"new"} .{:id=>"19"} {"id"=>"19", "controller"=>"invoices", "action"=>"edit"} .{:id=>"20"} {"id"=>"20", "controller"=>"invoices", "action"=>"edit"} {:controller=>"devise/ sessions", :action=>"new", :use_route=>"login", :only_path=>true} . {:invoice=>{:due_on=>"2013-05-14", :client_id=>"42", :notes=>"value for notes"}} Friday, August 9, 13

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OUTPUT AND STOP #activesupport-3.2.12/lib/active_support/core_ext/hash classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys raise self # stop running! dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you Friday, August 9, 13

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ADD A CONDITION #activesupport-3.2.12/lib/active_support/core_ext/hash classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys raise self if <some condition> dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you Friday, August 9, 13

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KEEP TRACK OFLOCATION #activesupport-3.2.12/lib/active_support/core_ext/hash class Hash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys p __FILE__, __LINE__ dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you Friday, August 9, 13

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LABEL WITH LOCATION #activesupport-3.2.12/lib/active_support/core_ext/hash classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys p “#{__FILE__}:#{__LINE__}” => self dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you Friday, August 9, 13

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TAG WITH ANAME #activesupport-3.2.12/lib/active_support/core_ext/hash class Hash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys p :broken_hash => self dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you Friday, August 9, 13

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CLEAN IT UP #activesupport-3.2.12/lib/active_support/core_ext/hash classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys require ‘pp’ pp self dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. Friday, August 9, 13

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OTHER USEFUL QUESTIONS Friday, August9, 13

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HOW DID IGET HERE? Friday, August 9, 13

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HOW DID IGET HERE? #activesupport-3.2.12/lib/active_support/core_ext/hash class Hash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys require ‘pp’ pp caller[0..10] dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. Friday, August 9, 13

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“DOES THIS FILELOAD?” module SomePossiblyIncludedMonkeyPatch def change_important_class_behavior # ... # ... end def obscure_some_key_method # ... # ... end end Friday, August 9, 13

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“DOES THIS FILELOAD?” raise “Yes, somebody required me” module SomePossiblyIncludedMonkeyPatch def change_important_class_behavior # ... # ... end def obscure_some_key_method # ... # ... end end Friday, August 9, 13

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“WHY DIDN’T THISFILE LOAD?” Friday, August 9, 13

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“WHY DIDN’T THISFILE LOAD?” require ‘some_library/some_junk’ module MyNiftyBehavior def stuff Friday, August 9, 13

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“WHY DIDN’T THISFILE LOAD?” require ‘some_library/some_junk’ module MyNiftyBehavior def stuff $ rspec spec/ No such file to load -- some_library/some_junk (LoadError) Friday, August 9, 13

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“WHY DIDN’T THISFILE LOAD?” require ‘some_library/some_junk’ module MyNiftyBehavior def stuff $ rspec spec/ No such file to load -- some_library/some_junk (LoadError) ... pretty print the search path Friday, August 9, 13

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“WHY DIDN’T THISFILE LOAD?” require ‘some_library/some_junk’ module MyNiftyBehavior def stuff $ rspec spec/ No such file to load -- some_library/some_junk (LoadError) ... pretty print the search path require ‘pp’ pp $: require ‘some_library/some_junk’ module MyNiftyBehavior def stuff Friday, August 9, 13

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“WHO REQUIRED ME?” moduleSomePossiblyIncludedMonkeyPatch def change_important_class_behavior # ... # ... end def obscure_some_key_method # ... # ... end end Friday, August 9, 13

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“WHO REQUIRED ME?” p“Required By” => caller[0] module SomePossiblyIncludedMonkeyPatch def change_important_class_behavior # ... # ... end def obscure_some_key_method # ... # ... end end Friday, August 9, 13

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WHAT IF YOUDON’T KNOW THE RIGHT QUESTION YET? Friday, August 9, 13

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USE DEBUGGER! Friday, August9, 13

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YOUR GEMFILE source 'http://rubygems.org' gem'rails', '3.2.12' gem 'rack', '~> 1.4.0' gem 'rake' gem "will_paginate" gem 'devise' group :development, :test do gem 'rspec' gem 'rspec-rails' gem 'factory_girl_rails' gem 'debugger' end Friday, August 9, 13

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IN THE CODE classHash # Return a new hash with all keys converted to symbols, as # long as they respond to +to_sym+. # # { 'name' => 'Rob', 'years' => '28' }.symbolize_keys # #=> { :name => "Rob", :years => "28" } def symbolize_keys debugger dup.symbolize_keys! end alias_method :to_options, :symbolize_keys alias_method :to_options!, :symbolize_keys! # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. # Note that keys are NOT treated indifferently, meaning if you use strings for keys but assert symbols Friday, August 9, 13

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RUNNING IT Friday, August9, 13

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RUNNING IT $ railsserver -u Development Server: Friday, August 9, 13

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RUNNING IT $ railsserver -u Development Server: $ rspec -d spec/ rSpec: Friday, August 9, 13

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RUNNING IT Arbitrary Rubyscript: $ rdebug <command> $ rdebug rake db:seed Friday, August 9, 13

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WHO ARE YOU? #activesupport-3.2.12/lib/active_support/core_ext/hash classHash def symbolize_keys debugger dup.symbolize_keys! end Friday, August 9, 13

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WHO ARE YOU? (rdb:1)eval dup.class #activesupport-3.2.12/lib/active_support/core_ext/hash class Hash def symbolize_keys debugger dup.symbolize_keys! end Friday, August 9, 13

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WHO ARE YOU? (rdb:1)eval dup.class Hash #activesupport-3.2.12/lib/active_support/core_ext/hash class Hash def symbolize_keys debugger dup.symbolize_keys! end Friday, August 9, 13

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WHO AM I? (rdb:1)eval self.class Friday, August 9, 13

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WHO AM I? (rdb:1)eval self.class Hash Friday, August 9, 13

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WHO CAN ICALL? (rdb:1) eval self.methods Friday, August 9, 13

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WHO CAN ICALL? (rdb:1) eval self.methods [:specify, :class_variable_defined?, :public_class_method, :methods, :use_instantiated_fixtures=, :filtered_examples, :before_all_ivars, :should, :const_defined?, :untrust, :local_constant_names, :should_not, :capture, :module_eval, :instance_methods, :clone, :load_dependency, :to_json, :run_hook, :all_apply?, :share_examples_for, :include?, :redefine_method, :to_yaml, :respond_to?, :examples, :fail_fast?, :unloadable, :it_should_behave_like, :<=>, :instance_variable_defined?, :register, :acts_like?, :psych_yaml_as, :debug_method, :fixture_class_names, :let!, :render_views, :focus, :private_class_method, :delegate, :public_constant, :singleton_methods, :pretty_print_instance_variables, :attr_internal_writer, :use_instantiated_fixtures?, :matcher, :try, :tests, :as_json, :gem, :untrusted?, :controller_class, :pending, :parent, :silence, :class_eval, Friday, August 9, 13

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WHO CAN ICALL? (rdb:1) eval self.methods.sort Friday, August 9, 13

69.
WHO CAN ICALL? (rdb:1) eval self.methods.sort [:!, :!=, :!~, :<=>, :==, :===, :=~, :[], : []=, :__id__, :__send__, :`, :acts_like?, :all?, :any?, :as_json, :assert_valid_keys, :assoc, :binding_n, :blank?, :breakpoint, :capture, :chunk, :class, :class_eval, :clear, :clone, :collect, :collect_concat, :compare_by_identity, :compare_by_identity?, :count, :cycle, :dbg_print, :dbg_puts, :debugger, :deep_dup, :deep_merge, :deep_merge!, :deep_symbolize_keys, :default, :default=, :default_proc, :default_proc=, :define_singleton_method, :delete, :delete_if, :detect, :diff, :display, :drop, :drop_while, :dup, :duplicable?, :each, :each_cons, :each_entry, :each_key, :each_pair, :each_slice, :each_value, :each_with_index, :each_with_object, :empty?, :enable_warnings, :encode_json, :entries, :enum_for, :eql?, :equal?, :except, :except!, :exclude?, :extend, :extract!, :extractable_options?, :fetch, :find, :find_all, :find_index, Friday, August 9, 13

70.
WHO CAN ICALL? (rdb:1) eval self.methods.grep(/merge/) Friday, August 9, 13

71.
WHO CAN ICALL? (rdb:1) eval self.methods.grep(/merge/) [:deep_merge!, :reverse_merge!, :merge!, :merge, :deep_merge, :reverse_merge, :merge_resultset] Friday, August 9, 13

72.
DEBUGGER HAS ‘PP’ BYDEFAULT Friday, August 9, 13

73.
WHO DO YOUINCLUDE? (rdb:1) pp dup.class.included_modules Friday, August 9, 13

74.
WHO DO YOUINCLUDE? (rdb:1) pp dup.class.included_modules [SimpleCov::HashMergeHelper, JSON::Ext::Generator::GeneratorMethods::Hash, Enumerable, RSpec::Steps::ClassMethods, JSON::Ext::Generator::GeneratorMethods::Object, ActiveSupport::Dependencies::Loadable, PP::ObjectMixin, Kernel] Friday, August 9, 13

75.
FINDING METHODS Friday, August 9,13

76.
AT THE COMMAND-LINE -H(show ﬁlename) -n (show line number) -r (recurse directories) -i (ignore case -- use carefully) $ grep -Hnir <pattern> <path> Friday, August 9, 13

77.
USEFUL PATTERNS Friday, August9, 13

78.
USEFUL PATTERNS $ grep-Hnr “def *my_method” * Method deﬁnitions: Friday, August 9, 13

79.
USEFUL PATTERNS $ grep-Hnr “def *my_method” * Method deﬁnitions: $ grep <stuff> | grep -v “ *#” Ignore comments: Friday, August 9, 13

80.
ACK > GREP $ack <pattern> Friday, August 9, 13

81.
ACK > GREP Friday,August 9, 13

82.
ACK > GREP •Looksonly in programming ﬁles (ignores logs!) Friday, August 9, 13

83.
ACK > GREP •Looksonly in programming ﬁles (ignores logs!) •brew install ack Friday, August 9, 13

84.
ACK > GREP •Looksonly in programming ﬁles (ignores logs!) •brew install ack •Conﬁgurable via .ackrc Friday, August 9, 13

85.
ACK > GREP •Looksonly in programming ﬁles (ignores logs!) •brew install ack •Conﬁgurable via .ackrc •https://gist.github.com/IdahoEv/5580770 Friday, August 9, 13

86.
BUT THEN THIS... Friday,August 9, 13

87.
BUT THEN THIS... $ack “def *my_method” Friday, August 9, 13

88.
BUT THEN THIS... $ack “def *my_method” $ Friday, August 9, 13

89.
BUT THEN THIS... $ack “def *my_method” $ ... it doesn’t exist Friday, August 9, 13

90.
BUT THEN THIS... $ack “def *my_method” $ ... it doesn’t exist Friday, August 9, 13

91.
BECAUSE RUBY LETS YOUDO THIS... Friday, August 9, 13

92.
module RSpec module Core classExampleGroup class << self delegate_to_metadata :described_class, :file_path alias_method :display_name, :description alias_method :describes, :described_class # @private # @macro [attach] define_example_method # @param [String] name # @param [Hash] extra_options # @param [Block] implementation def self.define_example_method(name, extra_options={}) module_eval(<<-END_RUBY, __FILE__, __LINE__) def #{name}(desc=nil, *args, &block) options = build_metadata_hash_from(args) options.update(:pending => RSpec::Core::Pending::) unless block options.update(#{extra_options.inspect}) examples << RSpec::Core::Example.new(self, desc, options, block) examples.last end END_RUBY end define_example_method :example define_example_method :it define_example_method :specify define_example_method :focus, :focused => true, :focus => true Friday, August 9, 13

93.
module RSpec module Core classExampleGroup class << self delegate_to_metadata :described_class, :file_path alias_method :display_name, :description alias_method :describes, :described_class # @private # @macro [attach] define_example_method # @param [String] name # @param [Hash] extra_options # @param [Block] implementation def self.define_example_method(name, extra_options={}) module_eval(<<-END_RUBY, __FILE__, __LINE__) def #{name}(desc=nil, *args, &block) options = build_metadata_hash_from(args) options.update(:pending => RSpec::Core::Pending::) unless block options.update(#{extra_options.inspect}) examples << RSpec::Core::Example.new(self, desc, options, block) examples.last end END_RUBY end define_example_method :example define_example_method :it define_example_method :specify define_example_method :focus, :focused => true, :focus => true Friday, August 9, 13

94.
ADVANCED INTROSPECTION Friday, August 9,13

95.
WHO DO YOUINCLUDE? #activesupport-3.2.12/lib/active_support/core_ext/hash class Hash # ... snip ... def symbolize_keys debugger dup.symbolize_keys! end # ... snip ... end Friday, August 9, 13

96.
WHO DO YOUINCLUDE? (rdb:1) pp self.class.included_modules [SimpleCov::HashMergeHelper, JSON::Ext::Generator::GeneratorMethods::Hash, Enumerable, RSpec::Steps::ClassMethods, JSON::Ext::Generator::GeneratorMethods::Object, ActiveSupport::Dependencies::Loadable, PP::ObjectMixin, Kernel] Friday, August 9, 13

97.
WHO DEFINED THATMETHOD? (rdb:1) eval self.method(:merge_resultset).owner Friday, August 9, 13

98.
WHO DEFINED THATMETHOD? (rdb:1) eval self.method(:merge_resultset).owner SimpleCov::HashMergeHelper Friday, August 9, 13

99.
BUT DEFINED WHERE? (rdb:1)pp self.method(:merge_resultset).source_location Friday, August 9, 13

100.
BUT DEFINED WHERE? (rdb:1)pp self.method(:merge_resultset).source_location ["~/evan/.rvm/gems/ruby-1.9.3-p327-fast@tracks/gems/ simplecov-0.5.4/lib/simplecov/merge_helpers.rb", 25] Friday, August 9, 13

101.
EVEN WORKS ON DYNAMICMETHODS! Friday, August 9, 13

102.
EVEN WORKS ON DYNAMICMETHODS! #/spec/controllers/invoices_controller_spec.rb require 'spec_helper' describe InvoicesController do debugger describe "as an admin" do before(:each) do authenticate(:admin) Friday, August 9, 13

103.
EVEN WORKS ON DYNAMICMETHODS! (rdb:1) eval method(:example).source_location Friday, August 9, 13

104.
EVEN WORKS ON DYNAMICMETHODS! (rdb:1) eval method(:example).source_location ["/Volumes/Valinor/Users/evan/.rvm/gems/ruby-1.9.3-p327- fast@tracks/gems/rspec-core-2.13.1/lib/rspec/core/ example_group.rb", 61] Friday, August 9, 13

105.
WHERE TO LOOKNEXT •Pry (https://github.com/pry/pry) •API Docs: http://www.ruby-doc.org/core-2.0 • Kernel • Module • Method Friday, August 9, 13

106.
Thanks! Evan Dorn Founder, LogicalReality Design http://lrdesign.com evan@lrdesign.com @idahoev Text Friday, August 9, 13

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