GitPedia

Factory trace

Simple tool to maintain factories and traits from FactoryBot

From djezzzl·Updated June 3, 2026·View on GitHub·

**factory trace** is a Simple tool to maintain factories and traits from FactoryBot The project is written primarily in Ruby, distributed under the MIT License license, first published in 2019. Key topics include: factory-bot, factory-girl, minitest, rspec, ruby.

FactoryTrace

Gem Version


The main goal of the project is to provide an easy way to maintain FactoryBot
factories and Rails fixtures
inside your project in a good shape.

If the project helps you or your organization, I would be very grateful if you contribute or donate.
Your support is an incredible motivation and the biggest reward for my hard work.

Follow me and stay tuned for the updates:

What it does?

Currently, it helps to find unused factories, traits, and Rails fixtures.

Example output for FactoryBot (from Rails RSpec Example):

bash
$ FB_TRACE=1 rspec total number of unique used factories & traits: 3 total number of unique unused factories & traits: 3 unused factory admin => spec/factories.rb:10 unused trait with_address of factory admin => spec/factories.rb:11 unused global trait with_email => spec/factories.rb:16

Example output for Rails fixtures with Minitest (but can be with RSpec, too):

bash
$ FB_TRACE=1 rails test total number of unique used fixture sets & entries: 2 total number of unique unused fixture sets & entries: 2 unused fixture entry two of fixture set users => test/fixtures/users.yml:7 unused fixture set companies => test/fixtures/companies.yml:1

Installation

Add this line to your application's Gemfile in the group you have factory_bot or factory_bot_rails:

ruby
gem 'factory_trace'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install factory_trace

Usage

The gem supports RSpec and Minitest out of the box.
You don't need to add any hooks. Just run the tests, e.g.

bash
# output to STDOUT FB_TRACE=1 rspec # OR output to any file FB_TRACE_FILE=log/factory_trace.txt rspec # Minitest works the same way FB_TRACE=1 ruby -Itest test/my_test.rb # OR output to any file FB_TRACE_FILE=log/factory_trace.txt ruby -Itest test/my_test.rb

For any other case, add the following line where you want to start
tracking usage of FactoryBot factories and traits:

ruby
FactoryTrace.start

Add this line where you want to stop tracking and get collected information:

ruby
FactoryTrace.stop

Partial execution

Imagine, you run your specs in parts (as many as you need) and then want to track total usage of
factories and traits. For that, we have a trace_only mode. You can try following commands here.

bash
# one part FB_TRACE=trace_only FB_TRACE_FILE=fb_trace_result1.json bundle exec rspec spec/first_spec.rb # another part FB_TRACE=trace_only FB_TRACE_FILE=fb_trace_result2.json bundle exec rspec spec/second_spec.rb # output the usage to the console bundle exec factory_trace fb_trace_result1.json fb_trace_result2.json # or to the file FB_TRACE_FILE=fb_report.txt bundle exec factory_trace fb_trace_result1.json fb_trace_result2.json

Note: bundle exec factory_trace won't load your project. Thus it runs fast and it's easier to configure it on CI.

Configuration

You can configure FactoryTrace:

ruby
FactoryTrace.configure do |config| # default ENV.key?('FB_TRACE') || ENV.key?('FB_TRACE_FILE') config.enabled = true # default is ENV['FB_TRACE_FILE'] # when nil outputs to STDOUT config.path = 'log/factory_trace.txt' # default is true when +path+ is nil config.color = true # default is ENV['FB_TRACE'] || :full # can be :full or :trace_only config.mode = :full # used to trace definitions places # default is true # can be true or false config.trace_definition = true # path (or array of paths) to the Rails fixtures directory # default is 'test/fixtures' # set to nil to disable fixture tracking config.fixture_path = 'test/fixtures' end

Tip: if you have some errors try to disable trace_definition. That functionality does
many monkey patches to FactoryBot. I will appreciate sharing an error stack trace so I can
fix it.

Development

After checking out the repo, run bundle install to install dependencies.
Then, run rake spec to run the tests.
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.

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Contributing

Bug reports and pull requests are welcome on GitHub.
This project is intended to be a safe, welcoming space for collaboration, and contributors are expected
to adhere to the Contributor Covenant code of conduct.

License

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

Code of Conduct

Everyone interacting in the FactoryTrace project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.

Changelog

FactoryTrace's changelog is available here.

Copyright (c) Evgeniy Demin. See LICENSE.txt for further details.

Contributors

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View all contributors on GitHub →

This article is auto-generated from djezzzl/factory_trace via the GitHub API.Last fetched: 6/29/2026