Fix eager loading of scoped associations. Previously the scope was no… (

#67)

* Fix eager loading of scoped associations. Previously the scope was not applied.  Scopes that accept arguments cannot be used as they are expecting an instance to be passed to them and if we are eager loading there is no instance to reference.

* Update CHANGELOG.

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Not released
 
+- Fix eager loading of scoped associations. (https://github.com/Beyond-Finance/active_force/pull/67)
 - Adding `.blank?`, `.present?`, and `.any?` delegators to `ActiveQuery`. (https://github.com/Beyond-Finance/active_force/pull/68)
 - Adding `update` and `update!` class methods on `SObject`. (https://github.com/Beyond-Finance/active_force/pull/66)
 

lib/active_force/association/association.rb

@@ -26,6 +26,14 @@ def relationship_name
         options[:relationship_name] || relation_model.to_s.constantize.table_name
       end
 
+      def scoped_as
+        options[:scoped_as] || nil
+      end
+
+      def scoped?
+        options[:scoped_as].present?
+      end
+
       ###
       # Does this association's relation_model represent
       # +sfdc_table_name+? Examples of +sfdc_table_name+

lib/active_force/association/eager_load_projection_builder.rb

@@ -1,5 +1,6 @@
 module ActiveForce
   module Association
+    class InvalidEagerLoadAssociation < StandardError; end
     class EagerLoadProjectionBuilder
       class << self
         def build(association, parent_association_field = nil)
@@ -34,6 +35,13 @@ def initialize(association, parent_association_field = nil)
       def projections
         raise "Must define #{self.class.name}#projections"
       end
+
+      def apply_association_scope(query)
+        return query unless association.scoped?
+        raise InvalidEagerLoadAssociation, "Cannot use scopes that expect arguments: #{association.relation_name}" if association.scoped_as.arity.positive?
+
+        query.instance_exec(&association.scoped_as)
+      end
     end
 
     class HasManyAssociationProjectionBuilder < AbstractProjectionBuilder
@@ -43,17 +51,17 @@ class HasManyAssociationProjectionBuilder < AbstractProjectionBuilder
       # to be pluralized
       def projections
         relationship_name = association.sfdc_association_field
-        query = Query.new relationship_name
+        query = ActiveQuery.new(association.relation_model, relationship_name)
         query.fields association.relation_model.fields
-        ["(#{query.to_s})"]
+        ["(#{apply_association_scope(query).to_s})"]
       end
     end
 
     class HasOneAssociationProjectionBuilder < AbstractProjectionBuilder
       def projections
-        query = Query.new association.sfdc_association_field
+        query = ActiveQuery.new(association.relation_model, association.sfdc_association_field)
         query.fields association.relation_model.fields
-        ["(#{query.to_s})"]
+        ["(#{apply_association_scope(query).to_s})"]
       end
     end
 

spec/active_force/sobject/includes_spec.rb

@@ -225,6 +225,13 @@ module ActiveForce
           end
         end
 
+        context 'when assocation has a scope' do
+          it 'formulates the correct SOQL query with the scope applied' do
+            soql = Post.includes(:impossible_comments).where(id: '1234').to_s
+            expect(soql).to eq "SELECT Id, Title__c, BlogId, (SELECT Id, PostId, PosterId__c, FancyPostId, Body__c FROM Comments__r WHERE (1 = 0)) FROM Post__c WHERE (Id = '1234')"
+          end
+        end
+
         context 'with namespaced SObjects' do
           it 'formulates the correct SOQL query' do
             soql = Salesforce::Quota.includes(:prez_clubs).where(id: '123').to_s
@@ -286,9 +293,26 @@ module ActiveForce
         end
       end
 
+      context 'has_one' do
+        context 'when assocation has a scope' do
+          it 'formulates the correct SOQL query with the scope applied' do
+            soql = Post.includes(:last_comment).where(id: '1234').to_s
+            expect(soql).to eq "SELECT Id, Title__c, BlogId, (SELECT Id, PostId, PosterId__c, FancyPostId, Body__c FROM Comment__r WHERE (NOT ((Body__c = NULL))) ORDER BY CreatedDate DESC) FROM Post__c WHERE (Id = '1234')"
+          end
+        end
+
+      end
+
       context 'when invalid associations are passed' do
-        it 'raises an error' do
-          expect { Quota.includes(:invalid).find('123') }.to raise_error(ActiveForce::Association::InvalidAssociationError, 'Association named invalid was not found on Quota')
+        context 'when the association is not defined' do
+          it 'raises an error' do
+            expect { Quota.includes(:invalid).find('123') }.to raise_error(ActiveForce::Association::InvalidAssociationError, 'Association named invalid was not found on Quota')
+          end
+        end
+        context 'when the association is scoped and accepts an argument' do
+          it 'raises and error' do
+            expect { Post.includes(:reply_comments).find('1234')}.to raise_error(ActiveForce::Association::InvalidEagerLoadAssociation)
+          end
         end
       end
     end