Rspec: Should be (this or that)

Question

What would be the best way to write the rspec in a situation where either of two (or more) outcomes are acceptable?

Here\'s an example of what I want to do. This is

Answer 1

ActiveSupport provides Object#in? method. You can combine it with RSpec and simply use the following:

flip_coin.should be_in(["heads", "tails"])

Or with new Rspec 3 syntax:

expect(flip_coin).to be_in(["heads", "tails"])