3 files changed, 39 insertions, 0 deletions
diff --git a/activerecord/test/cases/nested_attributes_test.rb b/activerecord/test/cases/nested_attributes_test.rb
index aa519fd332..bb1c1ea17d 100644
--- a/activerecord/test/cases/nested_attributes_test.rb
+++ b/activerecord/test/cases/nested_attributes_test.rb
@@ -217,6 +217,18 @@ class TestNestedAttributesInGeneral < ActiveRecord::TestCase
     mean_pirate.parrot_attributes = { name: "James" }
     assert_equal "James", mean_pirate.parrot.name
   end
+
+  def test_should_not_create_duplicates_with_create_with
+    Man.accepts_nested_attributes_for(:interests)
+
+    assert_difference("Interest.count", 1) do
+      Man.create_with(
+        interests_attributes: [{ topic: "Pirate king" }]
+      ).find_or_create_by!(
+        name: "Monkey D. Luffy"
+      )
+    end
+  end
 end
 
 class TestNestedAttributesOnAHasOneAssociation < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index d03b412efb..c14dc23cf3 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -9,6 +9,7 @@ require "models/comment"
 require "models/author"
 require "models/entrant"
 require "models/developer"
+require "models/project"
 require "models/person"
 require "models/computer"
 require "models/reply"
@@ -1405,6 +1406,16 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal "cock", hens.new.name
   end
 
+  def test_create_with_nested_attributes
+    assert_difference("Project.count", 1) do
+      developers = Developer.where(name: "Aaron")
+      developers = developers.create_with(
+        projects_attributes: [{ name: "p1" }]
+      )
+      developers.create!
+    end
+  end
+
   def test_except
     relation = Post.where(author_id: 1).order("id ASC").limit(1)
     assert_equal [posts(:welcome)], relation.to_a
diff --git a/activerecord/test/cases/scoping/default_scoping_test.rb b/activerecord/test/cases/scoping/default_scoping_test.rb
index e3a34aa50d..6281712df6 100644
--- a/activerecord/test/cases/scoping/default_scoping_test.rb
+++ b/activerecord/test/cases/scoping/default_scoping_test.rb
@@ -4,6 +4,7 @@ require "cases/helper"
 require "models/post"
 require "models/comment"
 require "models/developer"
+require "models/project"
 require "models/computer"
 require "models/vehicle"
 require "models/cat"
@@ -366,6 +367,21 @@ class DefaultScopingTest < ActiveRecord::TestCase
     assert_equal "Jamis", jamis.name
   end
 
+  def test_create_with_takes_precedence_over_where
+    developer = Developer.where(name: nil).create_with(name: "Aaron").new
+    assert_equal "Aaron", developer.name
+  end
+
+  def test_create_with_nested_attributes
+    assert_difference("Project.count", 1) do
+      Developer.create_with(
+        projects_attributes: [{ name: "p1" }]
+      ).scoping do
+        Developer.create!(name: "Aaron")
+      end
+    end
+  end
+
   # FIXME: I don't know if this is *desired* behavior, but it is *today's*
   # behavior.
   def test_create_with_empty_hash_will_not_reset