I want to see what methods are unique to a class instance (class Pathname). I do:
Rails.root.class.methods(false)
And I get:
[:getwd, :pwd, :glob]
Then, I call one of the methods:
Rails.root.pwd
And I get:
NoMethodError (undefined method `pwd' for #<Pathname:/Users/borjagvo/workstation/npilookup>)
Why do I get this error? How can I see the public methods for instances of Pathname only?
Thanks!
You have to call class methods on class, like
Rails.root.class.pwd
OR
Pathname.pwd
For getting all instance methods (no ancestors nor singleton):
pry(main)> Rails.root.class.instance_methods(false) # OR Pathname.instance_methods(false)
=> [:write, :join, :+, :/, :as_json, :directory?, :exist?, :readable?,
:readable_real?, :world_readable?, :writable?, :writable_real?,
:world_writable?, :executable?, :executable_real?, :file?, :size? .....]
# Then you can call above methods on instance of a Pathname
pry(main)> Rails.root.size?
=> 1248
You are fetching the methods from the class of Rails.root, i.e. Pathname's class methods:
Rails.root.class #=> Pathname
Pathname.methods(false) #=> [:glob, :getwd, :pwd
To get the instance's methods, use:
Rails.root.methods
#=> [:mountpoint?, :root?, :each_filename, :descend, :ascend, :write, ...]
Or, to get its singleton methods: (there are none, it's an ordinary Pathname)
Rails.root.methods(false)
#=> []
Note that Rails.root is an instance of Pathname and already represents your app's working directory:
Rails.root
#=> #<Pathname:/Users/borjagvo/workstation/npilookup>
Rails.root.class.instance_methods(false)do anything for you?