Merge pull request #1348 from no-reply/fast-each

Implement enumeration for `Relation#each`

lib/active_fedora/associations/collection_proxy.rb

@@ -41,6 +41,8 @@ def initialize(association)
         merge! association.scope(nullify: false)
       end
 
+      delegate :each, to: :to_a
+
       def target
         @association.target
       end

lib/active_fedora/relation.rb

@@ -144,6 +144,16 @@ def scope_for_create
       @scope_for_create ||= where_values_hash.merge(create_with_value)
     end
 
+    def each
+      if loaded?
+        @records.each { |item| yield item } if block_given?
+        @records.to_enum
+      else
+        find_each(where_values) { |item| yield item } if block_given?
+        enum_for(:find_each, where_values)
+      end
+    end
+
     private
 
       VALID_FIND_OPTIONS = [:order, :limit, :start, :conditions, :cast].freeze

lib/active_fedora/relation/delegation.rb

@@ -13,7 +13,8 @@ module Delegation # :nodoc:
       :keep_if, :pop, :shift, :delete_at, :select!
     ].to_set
 
-    delegate :length, :collect, :map, :each, :all?, :include?, :to_ary, to: :to_a
+    delegate :length, :map, :to_ary, to: :to_a
+    delegate :all?, :blank?, :collect, :include?, :present?, to: :each
 
     protected
 

spec/integration/relation_spec.rb

@@ -41,6 +41,40 @@ class Book < ActiveFedora::Base
         expect_any_instance_of(ActiveFedora::Relation).to_not receive :find_each
         libraries[0]
       end
+
+      it "does not reload" do
+        expect_any_instance_of(ActiveFedora::Relation).to_not receive :find_each
+        libraries.each { |l| l.id }
+      end
+    end
+
+    describe '#each' do
+      before { Book.create }
+
+      it 'returns an enumerator' do
+        expect(libraries.each).to be_a Enumerator
+      end
+
+      it 'yields the items' do
+        expect { |b| libraries.each(&b) }
+          .to yield_successive_args(*Library.all.to_a)
+      end
+
+      it 'when called from Base yields all items' do
+        expect { |b| ActiveFedora::Base.all.each(&b) }
+          .to yield_successive_args(*(Library.all.to_a + Book.all.to_a))
+      end
+
+      context 'when cached' do
+        it 'returns an enumerator' do
+          expect(libraries.each).to be_a Enumerator
+        end
+
+        it 'yields the items' do
+          expect { |b| libraries.each(&b) }
+            .to yield_successive_args(*Library.all.to_a)
+        end
+      end
     end
 
     describe "#find" do