jimnanney/rubocop-env

Rubocop Cop to prevent assignment to ENV in rspec tests

RuboCop Env

RuboCop cop used to prevent direct assignment to ENV in rspec tests.

Env/Assign

Checks for any assignments to the ENV in tests.

When assigning to ENV you assign to a global state. This can affect other tests when you do not reassign the original value back to the ENV. This also can affect other tests when you are running tests in separate threads. This can lead to flaky and hard to find bugs in your test suite. It is much safer to mock the return value of the index getter to return the correct value.

 # bad
 ENV["OPTS"] = "testopts"

 # good
 allow(ENV).to receive(:[]).and_call_original
 allow(ENV).to receive(:[]).with("OPTS").and_return("testopts")

Installation

Add this line to your application's Gemfile:

gem 'rubocop-env', require: false

And then execute:

$ bundle install

Or install it yourself as:

$ gem install rubocop-env

Usage

In order to use this you'll need to tell Rubocop to load this extension. You can do it in one of three ways.

RuboCop

Add the following to your .rubocop.yml

require: rubocop-env

Requiring like this will automatically load the rubocop-env cops with the regular RoboCop cops.

Command line

rubocop --require rubocop-env

Rake task

RuboCop::RakeTask.new do |task|
  task.requires << 'rubocop-env'
end

Development

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 the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/rubocop-env. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the 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 Rubocop::Env project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.