rspec-must
rspec-must allows you to use #must instead of #should instance method in your specs. Currently it also provides #must_not and #must_receive, respectively aliased on #should_not and #should_receive.
Using "should" verb in specs may feel "wrong" to you. Especially if you are used to reading or implementing RFC, you will know about RFC 2119.
Usage
You need to require 'rspec' in your spec_helper before requiring 'rspec/must' because rspec-must reopen a module created by rspec-mocks:
require 'rspec'
require 'rspec/must'
must* methods will be available where equivalent #should* methods
are.
Installation
rspec-must is a ruby gem, so you can use rubygems:
gem install rspec-must
Or if you use bundler, add it to your Gemfile.