• Do not use default positional arguments.
  Use keyword arguments (if available - in Ruby 2.0 or later) or an options
  hash instead.^[link]

    # bad
    def obliterate(things, gently = true, except = [], at = Time.now)
      ...
    end
    # good
    def obliterate(things, gently: true, except: [], at: Time.now)
      ...
    end
    # good
    def obliterate(things, options = {})
      options = {
        :gently => true, # obliterate with soft-delete
      }.merge(options)
      ...
    end

• Avoid single-line methods. Although
  they are somewhat popular in the wild, there are a few peculiarities about
  their definition syntax that make their use undesirable.
  ^[link]

    # bad
    def too_much; something; something_else; end
    # good
    def some_method
      # body
    end

Method calls

• If the method returns a value.
  ^[link]

• If the first argument to the method uses
  parentheses.^[link]

    # bad
    put! (x + y) % len, value
  

•   # bad
    f (3 + 2) + 1
    # good
    f(3 + 2) + 1

• Omit parentheses for a method call if the
  method accepts no arguments.^[link]

• If the method doesn’t return a value (or we
  don’t care about the return), parentheses are optional. (Especially if the
  arguments overflow to multiple lines, parentheses may add readability.)
  ^[link]

    # okay
    render(:partial => 'foo')
    # okay
    render :partial => 'foo'

• If a method accepts an options hash as the
  last argument, do not use { } during invocation.
  ^[link]

    # bad
    get '/v1/reservations', { :id => 54875 }
    get '/v1/reservations', :id => 54875