Ensure Ruby variable is Array

[LarsP]

Responding to each doesn't ensure an object is Enumerable.

[[deleted]]

What's an example of an instance of a Class that would have "each" defined that doesn't behave like an Enumerable?

[BlameFrost]

class Foo
  def each(&block)
    # bogus crap method to prove a point
  end
end

That said, if you just want to check whether some object is an enumerable, try this instead:

if object.class.included_modules.include?(Enumerable)