Est-il sûr d'exiger 'open-uri' dans un projet Rails?

Question

J'ai vu plein d'exemples d'open-uri, ça semble plutôt bien pour des choses simples. Cela me dérange vraiment que l'exiger définit une méthode nommée open dans la portée globale, cependant.

Cela est particulièrement troublant puisque, après farfouillé, il semble déjà dans une console Rails 5 à une méthode nommée open définie:

irb(main):001:0> open 
ArgumentError: wrong number of arguments (given 0, expected 1..3) 
     from (irb):1:in `initialize' 
     from (irb):1:in `open' 
     from (irb):1 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/console.rb:65:in `start' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/console_helper.rb:9:in `start' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/commands_tasks.rb:78:in `console' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/commands_tasks.rb:49:in `run_command!' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/command.rb:20:in `run' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands.rb:18:in `<top (required)>' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:302:in `require' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:302:in `block in require' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:268:in `load_dependency' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:302:in `require' 
     from /Users/ahamon/code/signist/bin/rails:9:in `<top (required)>' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:296:in `load' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:296:in `block in load' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:268:in `load_dependency' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:296:in `load' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/commands/rails.rb:6:in `call' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/command_wrapper.rb:38:in `call' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:185:in `block in serve' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:156:in `fork' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:156:in `serve' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:131:in `block in run' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:125:in `loop' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:125:in `run' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application/boot.rb:18:in `<top (required)>' 
     from /Users/ahamon/.rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' 
     from /Users/ahamon/.rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' 
     from -e:1:in `<main>'irb(main):002:0> 

Si j'aller de l'avant et require 'open-uri', la valeur de retour est true, et je l'ai maintenant effacé la open précédente, quelle qu'elle soit:

irb(main):002:0> require 'open-uri' 
=> true 
irb(main):003:0> open 
ArgumentError: wrong number of arguments (given 0, expected 1+) 
     from /Users/ahamon/.rubies/ruby-2.3.0/lib/ruby/2.3.0/open-uri.rb:29:in `open' 
     from (irb):3 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/console.rb:65:in `start' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/console_helper.rb:9:in `start' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/commands_tasks.rb:78:in `console' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands/commands_tasks.rb:49:in `run_command!' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/command.rb:20:in `run' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/railties-5.0.0.beta3/lib/rails/commands.rb:18:in `<top (required)>' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:302:in `require' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:302:in `block in require' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:268:in `load_dependency' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:302:in `require' 
     from /Users/ahamon/code/signist/bin/rails:9:in `<top (required)>' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:296:in `load' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:296:in `block in load' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:268:in `load_dependency' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/activesupport-5.0.0.beta3/lib/active_support/dependencies.rb:296:in `load' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/commands/rails.rb:6:in `call' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/command_wrapper.rb:38:in `call' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:185:in `block in serve' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:156:in `fork' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:156:in `serve' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:131:in `block in run' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:125:in `loop' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:125:in `run' 
     from /Users/ahamon/.gem/ruby/2.3.0/gems/spring-1.6.4/lib/spring/application/boot.rb:18:in `<top (required)>' 
     from /Users/ahamon/.rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' 
     from /Users/ahamon/.rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' 
     from -e:1:in `<main>'irb(main):004:0> 

les différents avis arité spécifié dans chaque trace de la pile.

Alors, quel est le open qui a été défini auparavant? Est-il sûr d'effacer? Existe-t-il un moyen d'utiliser open-uri sans définir les méthodes globales?

Answer 1

open est Kernel#open, pas Rails. open-uri wraps Kernel#open: il vérifie si la cible est une URL ou connaît #open, la gère si elle l'est, passe tout sur Kernel#open si ce n'est pas le cas.

Ainsi, sans open-uri, les URL ne fonctionnent pas, les fichiers ouverts ne fonctionnent pas, tout le reste. Avec open-uri, les URL fonctionnent, les openables fonctionnent, tout le reste est identique. Il ne devrait pas y avoir de danger à l'exiger, mis à part le très, très léger coup de performance lorsque open-uri vérifie si votre argument est une URL ou répond à #open.