Set ENV variables for specific tests

env_helpers.rb

# spec/support/env_helpers.rb

module EnvHelpers
  def with_env_vars(vars)
    original = ENV.to_hash
    vars.each { |k, v| ENV[k] = v }

    begin
      yield
    ensure
      ENV.replace(original)
    end
  end
end

RSpec.configure do |c|
  c.include EnvHelpers
end

#Then in any spec you can use this:

# it 'does something with the FOO environment variable' do
 # with_env_vars 'FOO' => 'bar' do
    # logic that depends upon ENV['FOO'] goes here
 # end
# end