RSpecOnFailure

Provide additional debugging information to be printed if a test fails.

In case the debugging information you want to display on failure cannot be easily determined prior to evaluating the expectation. This won't work as expected, for example:

expect(user).to be_valid, user.errors.full_messages

because user.errors.full_messages gets evaluated too soon. This will show the list of errors as it was prior to calling user.valid? (that is, an empty array), rather than the list of errors as it was after validating therecord, which is what we actually want.

Instead, you can do this, which defers evaluation of the debug information until the time of the failure:

   on_failure ->{ user.errors.full_messages } do
     expect(user).to be_valid
   end

If no block is given, the provided on_failure proc remains in effect until the end of the current example.

   on_failure ->{ user.errors.full_messages }
   expect(user).to be_valid
   expect(user.errors[:name]).to include "is required"

Add this line to your application's Gemfile:

group :test do
  gem 'rspec-on_failure'
end

And then execute:

$ bundle

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 rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/TylerRick/rspec-on_failure.