Array.wrap vs Kernel#Array

Both methods allow to convert an argument into an array but Kernel#Array has additional behavior:

• It tries to call to_ary and then to_a on the argument (Array.wrap immediately returns first element as single array item if object does not respond to to_ary method)
• If to_ary does not return nil or Array, it raises an exception

Array#wrap from ActiveSupport gem might be a better option for objects with custom to_a implementation such as LibXML::XML::Node#to_a (returns an array with a copy of the original node):

require 'libxml'
xml_node = LibXML::XML::Node.new('title', 'My title') # <LibXML::XML::Node:0x00007f98170995c8>
Array.wrap(xml_node) # [#<LibXML::XML::Node:0x00007f980b3e35f0>]
Array(xml_node) # [#<LibXML::XML::Node:0x00007f98170995c8>]

Array.wrap(xml_node).first.equal? Array.wrap(xml_node).first # true
Array(xml_node).first.equal? Array(xml_node).first # false

Id in Kernel#Array result is different than xml_node object’s id.

to_ary vs to_a

There is also a small difference between to_ary and to_a methods. The former one is used for treating object as an array (i.e. for implicit conversion) while latter one performs actual conversion.

Point = Struct.new(:x, :y) do
  def to_ary
    [x, y]
  end
end

p = Point.new(1, 2)
x, y = p

x # 1
y # 2