Merge pull request #16788 from codeodor/fix-16761

Skip StatementCache for eager loaded associations

activerecord/lib/active_record/associations/collection_association.rb

@@ -407,7 +407,7 @@ def null_scope?
 
       private
       def get_records
-        return scope.to_a if reflection.scope_chain.any?(&:any?)
+        return scope.to_a if reflection.scope_chain.any?(&:any?) || scope.eager_loading?
 
         conn = klass.connection
         sc = reflection.association_scope_cache(conn, owner) do

activerecord/lib/active_record/associations/singular_association.rb

@@ -39,7 +39,7 @@ def create_scope
         end
 
         def get_records
-          return scope.limit(1).to_a if reflection.scope_chain.any?(&:any?)
+          return scope.limit(1).to_a if reflection.scope_chain.any?(&:any?) || scope.eager_loading?
 
           conn = klass.connection
           sc = reflection.association_scope_cache(conn, owner) do

activerecord/lib/active_record/core.rb

@@ -152,6 +152,7 @@ def find(*ids)
 
       def find_by(*args)
         return super if current_scope || !(Hash === args.first) || reflect_on_all_aggregations.any?
+        return super if default_scopes.any?
 
         hash = args.first
 

activerecord/test/cases/scoping/default_scoping_test.rb

 require 'cases/helper'
 require 'models/post'
+require 'models/comment'
 require 'models/developer'
 
 class DefaultScopingTest < ActiveRecord::TestCase
-  fixtures :developers, :posts
+  fixtures :developers, :posts, :comments
 
   def test_default_scope
     expected = Developer.all.merge!(:order => 'salary DESC').to_a.collect { |dev| dev.salary }
@@ -378,6 +379,24 @@ def test_default_scope_include_with_count
     assert_equal 1, DeveloperWithIncludes.where(:audit_logs => { :message => 'foo' }).count
   end
 
+  def test_default_scope_with_references_works_through_collection_association
+    post = PostWithCommentWithDefaultScopeReferencesAssociation.create!(title: "Hello World", body: "Here we go.")
+    comment = post.comment_with_default_scope_references_associations.create!(body: "Great post.", developer_id: Developer.first.id)
+    assert_equal comment, post.comment_with_default_scope_references_associations.to_a.first
+  end
+
+  def test_default_scope_with_references_works_through_association
+    post = PostWithCommentWithDefaultScopeReferencesAssociation.create!(title: "Hello World", body: "Here we go.")
+    comment = post.comment_with_default_scope_references_associations.create!(body: "Great post.", developer_id: Developer.first.id)
+    assert_equal comment, post.first_comment
+  end
+
+  def test_default_scope_with_references_works_with_find_by
+    post = PostWithCommentWithDefaultScopeReferencesAssociation.create!(title: "Hello World", body: "Here we go.")
+    comment = post.comment_with_default_scope_references_associations.create!(body: "Great post.", developer_id: Developer.first.id)
+    assert_equal comment, CommentWithDefaultScopeReferencesAssociation.find_by(id: comment.id)
+  end
+
   unless in_memory_db?
     def test_default_scope_is_threadsafe
       threads = []

activerecord/test/models/comment.rb

@@ -52,3 +52,8 @@ class CommentThatAutomaticallyAltersPostBody < Comment
     comment.post.update_attributes(body: "Automatically altered")
   end
 end
+
+class CommentWithDefaultScopeReferencesAssociation < Comment
+  default_scope ->{ includes(:developer).order('developers.name').references(:developer) }
+  belongs_to :developer
+end

activerecord/test/models/post.rb

@@ -218,3 +218,9 @@ class PostThatLoadsCommentsInAnAfterSaveHook < ActiveRecord::Base
     post.comments.load
   end
 end
+
+class PostWithCommentWithDefaultScopeReferencesAssociation < ActiveRecord::Base
+  self.table_name = 'posts'
+  has_many :comment_with_default_scope_references_associations, foreign_key: :post_id
+  has_one :first_comment, class_name: "CommentWithDefaultScopeReferencesAssociation", foreign_key: :post_id
+end