Gem Version


fear-rspec is a set of rspec matchers for Fear.


Add this line to your application's Gemfile:

gem 'fear-rspec'

And then execute:

$ bundle

Or install it yourself as:

$ gem install fear-rspec


Load matchers:

require 'fear/rspec'

Try matchers

To match against a Failure, use be_failure_of matcher.

expect(Failure(ArgumentError)).to be_failure_of(ArgumentError) # passes
expect(Failure(ArgumentError)).to  be_failure_of(RuntimeError) # fails
expect(Success(5)).to                         be_failure_of(5) # fails

To match against a Success, use be_success_of matcher.

expect(5).not_to                  be_success_of(5) # passes
expect(Success(5)).to             be_success_of(5) # passes
expect(Success(1)).to             be_success_of(5) # fails
expect(Failure(ArgumentError)).to be_success_of(5) # fails

Either matchers

To match against a Left, use be_left_of matcher.

expect(5).not_to    be_left_of(5) # passes
expect(Left(5)).to  be_left_of(5) # passes
expect(Left(1)).to  be_left_of(5) # fails
expect(Right(5)).to be_left_of(5) # fails

To match against a Right, use be_right_of matcher.

expect(5).not_to    be_right_of(5) # passes
expect(Right(5)).to be_right_of(5) # passes
expect(Right(1)).to be_right_of(5) # fails
expect(Left(5)).to  be_right_of(5) # fails

Option matchers

To match against a Some, use be_some_of matcher.

expect(5).not_to   be_some_of(5)  # passes
expect(Some(5)).to be_some_of(5)  # passes
expect(Some(1)).to be_some_of(5)  # fails
expect(None()).to  be_some_of(5)  # fails

To match against a None, use be_none matcher.

expect(5).not_to   be_none # passes
expect(Some(5)).to be_none # fails
expect(None()).to  be_none # passes


After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to


  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 a new Pull Request


The gem is available as open source under the terms of the MIT License.