RSpec::ChangeCollection

RSpec::ChangeCollection provides the to_include and to_exclude methods to the change for blocks that return a collection.

Add this line to your application's Gemfile:

gem 'rspec-change_collection'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rspec-change_collection

And require it as:

require 'rspec/change_collection'

Use the to_include and to_exclude methods to make assertions about the effect of an rspec change block.

Both to_include and to_exclude accept objects or blocks. You can pass it a list of objects:

array = []
expect { array << 1 << 2 }.to change { array }.to_include 1, 2

And you can use block to make claims about any of the items before and after the change:

array = [1]
expect { array << 2 }.to change { array }.to_include(&:even?)

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request