Merging defaults with options hash in a ruby function

merge_defaults.rb

# Related area of style guide: https://github.com/GetJobber/ruby-style-guide#hash-fetch-defaults

# Pros: Is succinct and intuitive
# Cons: Doesn't work for false values
def default_one(options)
  options[:foo] ||= 'foo'
  options[:bar] ||= 'bar'
end

# Pros: Handles false without issue, is succient
# Cons: Less intuitive if you're not familiar with the behaviour of merge.  This line is somewhat cryptic: options = defaults.merge(options)
#       Involves shadowing "options" with a merged version of options.
def default_two(options)
  defaults = {:foo => 'foo', :bar => 'boo'}
  
  options = defaults.merge(options)
end

# Source: http://stackoverflow.com/questions/977535/whats-a-nice-clean-way-to-use-an-options-hash-with-defaults-values-as-a-paramet
# Pros: Handles false without issue, is even more succient than option 2, maybe more intuitive than option 2
# Cons: You're even less likely to intuitively know what a `reverse_merge` is than `merge`, but you can probably guess from context
def default_three(options)
  options.reverse_merge!{
    :foo => 'foo',
    :bar => 'bar'
  }
end

def default_four(options)
  options[:foo] = 'foo' unless options.has_key?(:foo)
  options[:bar] = 'bar' unless options.has_key?(:bar)
end

def default_five(options)
  options[:foo] = options.fetch(:foo, 'foo')
  options[:bar] = options.fetch(:bar, 'bar')
end

def default_six(options)
  defaults = {:foo => 'foo', :bar => 'boo'}
  
  options.reverse_merge!(defaults)
end

Decision, we'll run with default_six as our convention for now.