Find out what your Ruby gems are worth.
Appraisal integrates with bundler and rake to test your library against different versions of dependencies in repeatable scenarios called "appraisals." Appraisal is designed to make it easy to check for regressions in your library without interfering with day-to-day development using Bundler.
In your package's
Note that gems must be bundled in the global namespace. Bundling gems to a local location or vendoring plugins is not supported. If you do not want to pollute the global namespace, one alternative is RVM's Gemsets.
Setting up appraisal requires an
Appraisals file (similar to a
your project root, named "Appraisals" (note the case), and some slight changes
to your project's
Appraisals file consists of several appraisal definitions. An appraisal
definition is simply a list of gem dependencies. For example, to test with a
few versions of Rails:
appraise "rails-3" do gem "rails", "3.2.14" end appraise "rails-4" do gem "rails", "4.0.0" end
The dependencies in your
Appraisals file are combined with dependencies in
Gemfile, so you don't need to repeat anything that's the same for each
appraisal. If something is specified in both the Gemfile and an appraisal, the
version from the appraisal takes precedence.
Once you've configured the appraisals you want to use, you need to install the dependencies for each appraisal:
$ bundle exec appraisal install
This will resolve, install, and lock the dependencies for that appraisal using bundler. Once you have your dependencies set up, you can run any command in a single appraisal:
$ bundle exec appraisal rails-3 rake test
This will run
rake test using the dependencies configured for Rails 3. You can
also run each appraisal in turn:
$ bundle exec appraisal rake test
If you want to use only the dependencies from your Gemfile, just run
test as normal. This allows you to keep running with the latest versions of
your dependencies in quick test runs, but keep running the tests in older
versions to check for regressions.
In the case that you want to run all the appraisals by default when you run
rake, you can override your default Rake task by put this into your Rakefile:
if !ENV["APPRAISAL_INITIALIZED"] && !ENV["TRAVIS"] task :default => :appraisal end
APPRAISAL_INITIALIZED environment variable when it runs your
process. We put a check here to ensure that
appraisal rake command should run
your real default task, which usually is your
Note that this may conflict with your CI setup if you decide to split the test
into multiple processes by Appraisal and you are using
rake to run tests by
default. Please see Travis CI Integration for more detail.
appraisal clean # Remove all generated gemfiles and lockfiles from gemfiles folder appraisal generate # Generate a gemfile for each appraisal appraisal help [COMMAND] # Describe available commands or one specific command appraisal install # Resolve and install dependencies for each appraisal appraisal list # List the names of the defined appraisals appraisal update [LIST_OF_GEMS] # Remove all generated gemfiles and lockfiles, resolve, and install dependencies again appraisal version # Display the version and exit
Under the hood
appraisal install generates a Gemfile for each appraisal by combining
your root Gemfile with the specific requirements for each appraisal. These are
stored in the
gemfiles directory, and should be added to version control to
ensure that the same versions are always used.
When you prefix a command with
appraisal, the command is run with the
appropriate Gemfile for that appraisal, ensuring the correct dependencies
Removing Gems using Appraisal
It is common while managing multiple Gemfiles for dependencies to become deprecated and no
longer necessary, meaning they need to be removed from the Gemfile for a specific
To do this, use the
remove_gem declaration within the necessary
appraise block in your
gem 'rails', '~> 4.2' group :test do gem 'rspec', '~> 4.0' gem 'test_after_commit' end
appraise 'rails-5' do gem 'rails', '~> 5.2' group :test do remove_gem :test_after_commit end end
Appraisals file defined above, this is what the resulting
Gemfile will look like:
gem 'rails', '~> 5.2' group :test do gem 'rspec', '~> 4.0' end
When using Appraisal, we recommend you check in the Gemfiles that Appraisal
generates within the gemfiles directory, but exclude the lockfiles there
*.gemfile.lock.) The Gemfiles are useful when running your tests against a
continuous integration server such as Travis CI.
Travis CI integration
If you're using Appraisal and using Travis CI, we're recommending you to setup
Travis to run the test against multiple generated Gemfiles. This can be done
# In .travis.yml gemfile: - gemfiles/3.0.gemfile - gemfiles/3.1.gemfile - gemfiles/3.2.gemfile
Please note that if you've set your default rake task to run the test against
all versions of its dependency, you might have to set a
script: "bundle exec rake test"
That will make sure that each of the test sub-job are not getting run more than one time.
You can also run your tests against multiple versions of Ruby locally, just like running on Travis CI, by using WWTD.
Circle CI Integration
In Circle CI you can override the default testing behaviour to customize your testing. Using this feature you can configure appraisal to execute your tests.
In order to this you can put the following configuration in your circle.yml file:
dependencies: post: - bundle exec appraisal install test: pre: - bundle exec appraisal rake db:create - bundle exec appraisal rake db:migrate override: - bundle exec appraisal rspec
Notice that we are running an rspec suite. You can customize your testing
command in the
override section and use your favourite one.
Appraisal is maintained and funded by thoughtbot, inc
Thank you to all the contributors
The names and logos for thoughtbot are trademarks of thoughtbot, inc.
Appraisal is Copyright © 2010-2013 Joe Ferris and thoughtbot, inc. It is free software, and may be redistributed under the terms specified in the MIT-LICENSE file.