Allow custom resources to access all other resources (#3108)

Signed-off-by: Jared Quick <jquick@chef.io>

examples/custom-resource/README.md

@@ -0,0 +1,3 @@
+# Example Custom Resource Profile
+
+This example shows the implementation of an InSpec profile with custom resources.

examples/custom-resource/controls/example.rb

@@ -0,0 +1,7 @@
+# encoding: utf-8
+
+describe gordon do
+  its('crime_rate') { should be < 5 }
+  it { should have_a_fabulous_mustache }
+end
+

examples/custom-resource/inspec.yml

@@ -0,0 +1,8 @@
+name: custom_resource_example
+title: InSpec Profile
+maintainer: The Authors
+copyright: The Authors
+copyright_email: you@example.com
+license: Apache-2.0
+summary: An InSpec Compliance Profile
+version: 0.1.0

examples/custom-resource/libraries/batsignal.rb

@@ -0,0 +1,20 @@
+class Batsignal < Inspec.resource(1)
+  name 'batsignal'
+
+  example "
+      describe batsignal do
+        its('number_of_sightings)') { should eq '4' }
+      end
+  "
+
+  def number_of_sightings
+    local_command_call
+  end
+
+  private
+
+  def local_command_call
+    # call out to a core resource
+    inspec.command('echo 4').stdout.to_i
+  end
+end

examples/custom-resource/libraries/gordon.rb

@@ -0,0 +1,21 @@
+class Gordon < Inspec.resource(1)
+  name 'gordon'
+
+  example "
+    describe gordon do
+      its('crime_rate') { should be < 2 }
+      it { should have_a_fabulous_mustache }
+    end
+  "
+
+  def crime_rate
+    # call out ot another custom resource
+    inspec.batsignal.number_of_sightings
+  end
+
+  def has_a_fabulous_mustache?
+    # always true
+    true
+  end
+end
+

lib/inspec/resource.rb

@@ -50,8 +50,16 @@ module Inspec
           define_method id.to_sym do |*args|
             r.new(backend, id.to_s, *args)
           end
+
+          # confirm backend custom resources have access to other custom resources
+          next if backend.respond_to?(id)
+          backend.class.send(:define_method, id.to_sym) do |*args|
+            r.new(backend, id.to_s, *args)
+          end
         end
 
+        # attach backend so we have access to all resources and
+        # the train connection object
         define_method :inspec do
           backend
         end

test/functional/inspec_exec_test.rb

@@ -328,4 +328,13 @@ Test Summary: \e[38;5;41m2 successful\e[0m, 0 failures, 0 skipped\n"
       controls.select { |c| c['results'][0]['status'] == 'passed' }.count.must_be :>, 1
     end
   end
+
+  describe 'when using multiple custom resources with each other' do
+    let(:out) { inspec('exec ' + File.join(examples_path, 'custom-resource') + ' --no-create-lockfile') }
+
+    it 'completes the run with failed controls but no exception' do
+      out.stderr.must_be_empty
+      out.exit_status.must_equal 0
+    end
+  end
 end