Document and fix @disable-bundler hook

features/steps/environment/disable_bunder.feature

@@ -0,0 +1,18 @@
+Feature: Disable Bundler environment
+  Use the @disable-bundler tag to escape from your project's Gemfile.
+
+  Background:
+    Given I use the fixture "cli-app"
+
+  Scenario: Clear the Bundler environment
+
+    Given a file named "features/run.feature" with:
+    """
+    Feature: My Feature
+      @disable-bundler
+      Scenario: Check environment
+        When I run `env`
+        Then the output should not match /^BUNDLE_GEMFILE=/
+    """
+    When I run `cucumber`
+    Then the features should all pass

lib/aruba/api.rb

@@ -15,6 +15,7 @@
 require 'aruba/api/environment'
 require 'aruba/api/filesystem'
 require 'aruba/api/text'
+require 'aruba/api/bundler'
 require 'aruba/api/rvm'
 
 Aruba.platform.require_matching_files('../matchers/**/*.rb', __FILE__)
@@ -27,6 +28,7 @@ module Api
     include Aruba::Api::Commands
     include Aruba::Api::Environment
     include Aruba::Api::Filesystem
+    include Aruba::Api::Bundler
     include Aruba::Api::Rvm
     include Aruba::Api::Deprecated
     include Aruba::Api::Text

lib/aruba/api/bundler.rb

@@ -0,0 +1,16 @@
+require 'aruba/api/environment'
+
+module Aruba
+  module Api
+    module Bundler
+      include Environment
+
+      # Unset variables used by bundler
+      def unset_bundler_env_vars
+        %w[RUBYOPT BUNDLE_PATH BUNDLE_BIN_PATH BUNDLE_GEMFILE].each do |key|
+          delete_environment_variable(key)
+        end
+      end
+    end
+  end
+end

lib/aruba/api/rvm.rb

@@ -32,13 +32,6 @@ def use_clean_gemset(gemset)
           raise "I didn't understand rvm's output: #{all_stdout}"
         end
       end
-
-      # Unset variables used by bundler
-      def unset_bundler_env_vars
-        %w[RUBYOPT BUNDLE_PATH BUNDLE_BIN_PATH BUNDLE_GEMFILE].each do |key|
-          set_environment_variable(key, nil)
-        end
-      end
     end
   end
 end

spec/aruba/api/bundler_spec.rb

@@ -0,0 +1,15 @@
+require 'spec_helper'
+require 'aruba/api'
+
+RSpec.describe Aruba::Api::Bundler do
+  include_context 'uses aruba API'
+
+  describe '#unset_bundler_env_vars' do
+    it "sets up Aruba's environment to clear Bundler's variables" do
+      @aruba.unset_bundler_env_vars
+
+      expect(@aruba.aruba.environment['BUNDLE_PATH']).to be_nil
+      expect(@aruba.aruba.environment['BUNDLE_GEMFILE']).to be_nil
+    end
+  end
+end