Saves a history of rspec test outcomes, and provides a few tools to learn from that data (i.e. flakyness, performance regressions)


Add this line to your application's Gemfile:

gem 'rspec_log_formatter'


You can include the formatter in your suite, by configuring Rspec.

    RSpec.configure do |config|
      config.formatters <<
      config.formatters <<


Build number access

The formatter reads BUILD_NUMBER environment variable to separate specs into builds.

config.formatters <<
  build_number: ENV["MY_BUILD_NUMBER"]

Limit history length

The formatter keeps appending to rspec.history to keep track of spec outcomes. If you wish to limit this, you can specify how many builds to keep:

config.formatters <<
  limit_history: 4

Now it will only keep last 4 builds of history and truncate the rest. NOTE: this is separate from the AnalyzerFormatter option builds_to_analyze

Number of builds to analyze

Separate from the amount of history to keep, builds_to_analyze option, specifies how many of the recent builds to use when calculating test's flakyness.

config.formatters <<
  builds_to_analyze: 3

This instructs the analyzer to only use last 3 builds when calculating it's report.

What if I re-run my tests?

If you use something like 'rspec-rerun' gem to retry flaky tests, AnalyzerFormatter can estimate how much time does a flaky test is costing your test suite. Specify max_reruns to inform it of the max number of retries your suite is making.

config.formatters <<
  max_reruns: 3

How it works

Results of each of the tests in your test suite will go in rspec.history in the directory the rspec is ran from. What you'll see in there is output like this(columns separated by tabs):

654 2014-02-10 11:30:20 -0800   passed  Math works  ./spec/dummy_spec.rb            0.000722

The colums are as follows(tab separated):

BUILD_NUMBER    TIME_OF_RUN PASS/FAIL   example description example_filepath    exception.message   exception.class test_duration   


  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 new Pull Request