assert_matches_snapshot

An assertion for snapshot testing. Take a snapshot of response.body at any point during a Rails functional or integration test. If the contents of response.body later change, the assertion will fail.

Add this line to your application's Gemfile:

gem 'assert_matches_snapshot'

And then execute:

$ bundle

Or install it yourself as:

$ gem install assert_matches_snapshot

Add the following to any Rails functional or integration test:

assert_matches_snapshot 'after page is loaded'

assert_matches_snapshot takes one argument: a string that is used to distinguish snapshots from each other. This string should be unique across all tests for a controller-action combination.

To overwrite the snapshots, set the environment variable OVERWRITE_SNAPSHOTS=true before running your test command. For example, in a Linux environment:

$ OVERWRITE_SNAPSHOTS=true rails test

After checking out the repo, run bundle install to install dependencies. Then, run rake test to run the tests, or bundle exec guard to run the tests every time a file is changed.

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 rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/tbroadley/assert_matches_snapshot.

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