Merge pull request #23277 from kbrock/preload_associations

Avoid scope query when preloading

lib/miq_preloader.rb

@@ -22,9 +22,7 @@ module MiqPreloader
   #        Currently an array does not work
   # @return [Array<ActiveRecord::Base>] records
   def self.preload(records, associations, preload_scope = nil)
-    # Rails 7 changed the interface.  See rails commit: e3b9779cb701c63012bc1af007c71dc5a888d35a
-    # Note, added Array(records) as it could be a single element
-    ActiveRecord::Associations::Preloader.new(:records => Array(records), :associations => associations, :available_records => Array(preload_scope)).call
+    ActiveRecord::Associations::Preloader.new(:records => Array(records), :associations => associations, :scope => preload_scope).call
   end
 
   # for a record, cache results. Also cache the children's links back

spec/lib/extensions/ar_to_model_hash_spec.rb

@@ -70,7 +70,7 @@
 
     def assert_preloaded(associations)
       allow(ActiveRecord::Associations::Preloader).to receive(:new)
-        .with(:records => kind_of(Array), :associations => array_including(associations), :available_records => kind_of(Array))
+        .with(:records => kind_of(Array), :associations => array_including(associations), :scope => nil)
         .and_return(mocked_preloader)
       expect(mocked_preloader).to receive(:call)
 

spec/lib/miq_preloader_spec.rb

@@ -46,38 +46,28 @@
       emses = ExtManagementSystem.all.load
       vms   = Vm.where(:ems_id => emses.select(:id))
 
-      # TODO: With rails 7, the query count below increased by 1.
-      # This PR says only the singular associations are preloaded in rails 7:
-      # https://github.com/rails/rails/pull/42654
-      expect { preload(emses, :vms, vms) }.to make_database_queries(:count => 2)
+      expect { preload(emses, :vms, vms) }.to make_database_queries(:count => 1)
       expect { expect(emses.first.vms.size).to eq(2) }.not_to make_database_queries
     end
 
     # original behavior - not calling our code
     it "preloads with an unloaded simple relation" do
       vms = Vm.where(:ems_id => ems.id)
-      vms2 = vms.order(:id).to_a # preloaded vms to be used in tests
+      vms2 = vms.order(:id).load # preloaded vms to be used in tests
 
-      # TODO: With rails 7, the query count below increased by 1.
-      # This PR says only the singular associations are preloaded in rails 7:
-      # https://github.com/rails/rails/pull/42654
-      expect { preload(ems, :vms, vms) }.to make_database_queries(:count => 2)
+      expect { preload(ems, :vms, vms) }.to make_database_queries(:count => 1)
 
       expect { preload(ems, :vms, vms) }.not_to make_database_queries
       expect { expect(ems.vms).to match_array(vms2) }.not_to make_database_queries
 
-      # TODO: With rails 7, the query count below decreased by 1.
-      expect { expect(vms.first.ext_management_system).to eq(ems) }.to make_database_queries(:count => 1)
+      expect { expect(vms.first.ext_management_system).to eq(ems) }.to make_database_queries(:count => 2)
     end
 
     it "preloads with a loaded relation (records is a relation)" do
       ems
       emses = ExtManagementSystem.all.load
       vms   = Vm.where(:ems_id => emses.select(:id)).load
 
-      # TODO: With rails 7, the query count below increased by 1.
-      # This PR says only the singular associations are preloaded in rails 7:
-      # https://github.com/rails/rails/pull/42654
       expect { preload(emses, :vms, vms) }.to make_database_queries(:count => 1)
 
       expect { preload(emses, :vms, vms) }.not_to make_database_queries
@@ -97,36 +87,6 @@
       expect { expect(vms.first.ext_management_system).to eq(emses.first) }.not_to make_database_queries
     end
 
-    it "preloads with an array (records is a relation)" do
-      ems
-      emses = ExtManagementSystem.all.load
-      vms = Vm.where(:ems_id => emses.select(:id)).to_a
-      expect { preload(emses, :vms, vms) }.to make_database_queries(:count => 1)
-
-      expect { preload(emses, :vms, vms) }.not_to make_database_queries
-      expect { expect(emses.first.vms.size).to eq(2) }.not_to make_database_queries
-
-      # TODO: With rails 7, the query count below increased by 1.
-      # This PR says only the singular associations are preloaded in rails 7:
-      # https://github.com/rails/rails/pull/42654
-      expect { expect(vms.first.ext_management_system).to eq(ems) }.to make_database_queries(:count => 1)
-    end
-
-    it "preloads with an array (records is an array)" do
-      ems
-      emses = ExtManagementSystem.all.load.to_a
-      vms   = Vm.where(:ems_id => emses.map(&:id)).to_a
-      expect { preload(emses, :vms, vms) }.to make_database_queries(:count => 1)
-
-      expect { preload(emses, :vms, vms) }.not_to make_database_queries
-      expect { expect(emses.first.vms.size).to eq(2) }.not_to make_database_queries
-
-      # TODO: With rails 7, the query count below increased by 1.
-      # This PR says only the singular associations are preloaded in rails 7:
-      # https://github.com/rails/rails/pull/42654
-      expect { expect(vms.first.ext_management_system).to eq(ems) }.to make_database_queries(:count => 1)
-    end
-
     it "preloads a through with a loaded scope" do
       image
       nodes = ContainerNode.all.load