Convert ComplianceMixin to has_one/virtual_delegates

This converts the functionality defined in the virtual_has_one,
virtual_columns, and associated methods to a has_one and a pair of
virtual_delegates.

This allows these columns to also be used in SQL, and removes some of
the boilerplate code necessary for the methods that are defined.

app/models/mixins/compliance_mixin.rb

@@ -3,30 +3,19 @@ module ComplianceMixin
 
  included do
  has_many :compliances, :as => :resource, :dependent => :destroy
-
- virtual_has_one :last_compliance, :class_name => "Compliance"
-
- virtual_column :last_compliance_status, :type => :boolean, :uses => :last_compliance
- virtual_column :last_compliance_timestamp, :type => :datetime, :uses => :last_compliance
- end
-
- def last_compliance
- return @last_compliance unless @last_compliance.nil?
- @last_compliance = if @association_cache.include?(:compliances)
- compliances.max_by(&:timestamp)
- else
- compliances.order("timestamp DESC").first
- end
- end
-
- def last_compliance_status
- lc = last_compliance
- lc.try(:compliant)
- end
-
- def last_compliance_timestamp
- lc = last_compliance
- lc.try(:timestamp)
+ has_one :last_compliance,
+ -> { order('"compliances"."timestamp" DESC') },
+ :as => :resource,
+ :inverse_of => :resource,
+ :class_name => "Compliance"
+
+ virtual_delegate :last_compliance_status,
+ :to => "last_compliance.compliant",
+ :allow_nil => true
+ virtual_delegate :timestamp,
+ :to => :last_compliance,
+ :allow_nil => true,
+ :prefix => true
  end
 
  def check_compliance

spec/models/mixins/compliance_mixin_spec.rb

@@ -0,0 +1,50 @@
+describe ComplianceMixin do
+ include Spec::Support::ArelHelper
+
+ let(:host) { FactoryGirl.create(:host) }
+ let(:new_timestamp) { 2.months.ago.change(:usec => 0) }
+ let(:old_timestamp) { 4.months.ago.change(:usec => 0) }
+ let(:new_compliance) { FactoryGirl.create(:compliance, :resource => host, :timestamp => new_timestamp, :compliant => false) }
+ let(:old_compliance) { FactoryGirl.create(:compliance, :resource => host, :timestamp => old_timestamp) }
+ let(:compliances) { [old_compliance, new_compliance] }
+
+ describe "#last_compliance" do
+ it "uses the most recent value" do
+ compliances
+ expect(host.last_compliance.timestamp).to eq(new_timestamp)
+ end
+ end
+
+ describe "#last_compliance_status" do
+ context "with no compliances" do
+ it "is nil with sql" do
+ host
+ expect(virtual_column_sql_value(Host, "last_compliance_status")).to be_nil
+ end
+
+ it "is nil with ruby" do
+ expect(host.last_compliance_status).to be_nil
+ end
+ end
+
+ context "with compliances" do
+ before { compliances }
+
+ it "has the most recent timestamp with sql" do
+ h = Host.select(:id, :last_compliance_status).first
+
+ expect do
+ expect(h.last_compliance_status).to eq(false)
+ end.to match_query_limit_of(0)
+ expect(h.association(:last_compliance)).not_to be_loaded
+ end
+
+ it "has the most recent timestamp with ruby" do
+ h = Host.first # clean host record
+
+ expect(h.last_compliance_status).to eq(false)
+ expect(h.association(:last_compliance)).to be_loaded
+ end
+ end
+ end
+end