Set inverse associations when using scopes

Currently using scopes through a has_many association will not set the inverse association, e.g: product = Product.first product.variants.enabled.first.product.equal? product => false This commit fixes it by copying the association into the scope and then attempting to set the inverse association when the records are loaded.
JoeyButler · Aug 26, 2012 · 9f607fb · 9f607fb
1 parent ea84b0c
commit 9f607fb
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Showing 6 changed files with 35 additions and 5 deletions.
diff --git a/activerecord/lib/active_record/associations/association_scope.rb b/activerecord/lib/active_record/associations/association_scope.rb
@@ -15,6 +15,7 @@ def initialize(association)
 
       def scope
         scope = klass.unscoped
+        scope.association = @association
         scope.merge! eval_scope(klass, reflection.scope) if reflection.scope
         add_constraints(scope)
       end

diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -35,8 +35,8 @@ module Associations
     # instantiation of the actual post records.
     class CollectionProxy < Relation
       def initialize(association) #:nodoc:
-        @association = association
         super association.klass, association.klass.arel_table
+        @association = association
         merge! association.scope
       end
 
@@ -896,7 +896,7 @@ def ==(other)
       end
 
       # Returns a new array of objects from the collection. If the collection
-      # hasn't been loaded, it fetches the records from the database. 
+      # hasn't been loaded, it fetches the records from the database.
       #
       #   class Person < ActiveRecord::Base
       #     has_many :pets

diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
@@ -17,7 +17,7 @@ class Relation
     include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation
 
     attr_reader :table, :klass, :loaded
-    attr_accessor :default_scoped
+    attr_accessor :default_scoped, :association
     alias :model :klass
     alias :loaded? :loaded
     alias :default_scoped? :default_scoped
@@ -29,6 +29,7 @@ def initialize(klass, table, values = {})
       @implicit_readonly = nil
       @loaded            = false
       @default_scoped    = false
+      @association       = nil
     end
 
     def insert(values)
@@ -572,6 +573,10 @@ def exec_queries
         @records = default_scoped.to_a
       end
 
+      if association
+        @records.each { |record| association.set_inverse_instance(record) }
+      end
+
       @loaded = true
       @records
     end

diff --git a/activerecord/lib/active_record/relation/merger.rb b/activerecord/lib/active_record/relation/merger.rb
@@ -35,6 +35,10 @@ def initialize(relation, other)
           other = other.with_default_scope
         end
 
+        if other.association
+          relation.association = other.association
+        end
+
         @relation = relation
         @values   = other.values
       end

diff --git a/activerecord/test/cases/associations/inverse_associations_test.rb b/activerecord/test/cases/associations/inverse_associations_test.rb
@@ -261,8 +261,24 @@ def test_parent_instance_should_be_shared_with_replaced_via_accessor_children
 
   def test_parent_instance_should_be_shared_with_first_and_last_child
     man = Man.first
-    assert man.interests.first.man.equal? man
-    assert man.interests.last.man.equal? man
+    assert man.interests.first.man.equal?(man), "Man should be the same instance when using association.first"
+    assert man.interests.last.man.equal?(man), "Man should be the same instance when using association.last"
+  end
+
+  def test_parent_instance_should_be_shared_with_all_children
+    man = Man.first
+    assert man.interests.to_a.all?{ |interest| interest.man.equal?(man) }, "Man should be the same instance when using association.to_a"
+  end
+
+  def test_parent_instance_should_be_shared_with_first_and_last_child_when_using_scope
+    man = Man.first
+    assert man.interests.by_topic.first.man.equal?(man), "Man should be the same instance when using association.scope.first"
+    assert man.interests.by_topic.last.man.equal?(man), "Man should be the same instance when using association.scope.last"
+  end
+
+  def test_parent_instance_should_be_shared_with_all_children_when_using_scope
+    man = Man.first
+    assert man.interests.by_topic.to_a.all?{ |interest| interest.man.equal?(man) }, "Man should be the same instance when using association.scope.to_a"
   end
 
   def test_trying_to_use_inverses_that_dont_exist_should_raise_an_error

diff --git a/activerecord/test/models/interest.rb b/activerecord/test/models/interest.rb
@@ -2,4 +2,8 @@ class Interest < ActiveRecord::Base
   belongs_to :man, :inverse_of => :interests
   belongs_to :polymorphic_man, :polymorphic => true, :inverse_of => :polymorphic_interests
   belongs_to :zine, :inverse_of => :interests
+
+  def self.by_topic
+    order(arel_table[:topic])
+  end
 end