DannyBen / retest

A simple CLI to watch file changes and run their matching ruby specs. Works on any ruby projects with no setup.

Retest

Retest is a small command-line tool to help you refactor code by watching a file change and running its matching spec. Designed to be dev-centric and project independent, it can be used on the fly. No Gemfile updates, no commits to a repo or configuration files required to start refactoring. Works with every Ruby projects (at least that is the end goal)

Demo

retest-demo.mp4

Installation

Install it on your machine without adding it on a Gemfile:

$ gem install retest

Usage

Retest is used in your terminal after accessing your ruby project folder.

Help

Find out what retest can do anytime with

$ retest -h

For Refactoring

1. Run a hardcoded command

This the most simple usage of retest: running the same command over and over after each file update.

Example:

$ retest 'bundle exec rspec spec/features/posts_spec.rb'

In this example, the feature spec spec/features/posts_spec.rb will be tested after any ruby file is updated.

2. Run a dynamic command with placeholders

Retest provides few placeholders to help you run a command after every file change. The placeholders can be used on their own or together.

1. <test> placeholder

You can use the placeholder <test> to tell the gem where to put the test file path in your command. When a file is changed, the gem will find its matching test and run the test command with it.

Example:

$ retest 'bin/rails test <test>'

In this example, if app/models/post.rb is changed then retest will run bin/rails test test/models/post_test.rb

2. <changed> placeholder

You can use the placeholder <changed> to tell the gem where to put the changed file path in your command. When a file is changed, the gem will run the command with it.

Example:

$ retest 'rubocop <changed>'

In this example, if app/models/post.rb is changed then retest will run rubocop app/models/post.rb

3. Run a dynamic command with shortcuts

Few shortcut flags exist to avoid writing the full test command.

$ retest --rspec
$ retest --rails
$ retest --rake --all

4. Let retest figure it all out

Let retest find your ruby setup and run the appropriate command using:

$ retest
$ retest --all

Running rules

The gem works as follows:

• When a ruby file is changed, retest will run its matching test.
• When a test file is changed, retest will run the test file.
• When multiple matching test files are found, retest asks you to confirm the file and save the answer.
• When a test file is not found, retest runs the last run command or throw a 404.

Pull request scans

You can diff a branch and test all the relevant test files before pushing your branch and trigger a full CI suite.

$ retest --diff origin/main

In this example, retest lists all the files changed between HEAD and origin/main, finds all the relevant tests and only run those.

Why?

It is advised to be one cmd + z away from green tests when refactoring. This means running tests after every line change. Let Retest rerun your tests after every file change you make.

Retest gem is meant to be simple and follow testing conventions encountered in Ruby projects. Give it a go you can uninstall it easily. If you think the matching pattern could be improved please raise an issue.

For fully fledged solutions, some cli tools already exists: autotest, guard, zentest

Docker

Retest works in Docker too. You can install the gem and launch retest in your container while refactoring.

# Enter your container. Ex:
$ docker-compose run web bash

# Install the gem and run retest in your container shell
$ gem install retest
$ retest 'bundle exec rails test <test>'

Disclaimer

• If an error comes in try using bundle exec like so: $ retest 'bundle exec rake test <test>'
• Aliases saved on ~/.bashrc or ~/.zshrc cannot be run that way with the retest command

Ruby Support

Retest supports ruby 2.4 and above.

Roadmap

• MVP
• When multiple test files are found, ask which file to run and save the answer.
• When a test file is not found run the last command again.
• Run within Docker.
• Handle main Ruby setups
  • Bundler Gem
  • Rails
  • Ad-hoc scripts
  • Hanami
• Handle other languages: Go, Elixir, Node, Python, PHP
  • Go (project started)
• Aliases from oh-my-zsh and bash profiles?

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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.

To run integration tests on one setup (ex: hanami-app): bin/test/hanami-app

To access an app container (ex: ruby-app): docker-compose -f features/ruby-app/docker-compose.yml run retest sh

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/alexb52/retest.

License

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