From eeb5baa86f672021f18b59903a2090df407ab065 Mon Sep 17 00:00:00 2001
From: Ryuta Kamizono <kamipo@gmail.com>
Date: Fri, 5 Feb 2021 18:59:02 +0900
Subject: [PATCH] Merge pull request #41342 from
 kamipo/fix_build_on_association_relation

Fix `build` multiple records on association relation to not lose scope values
---
 .../lib/active_record/association_relation.rb | 10 ++++
 .../has_many_associations_test.rb             | 50 +++++++++++++++++--
 2 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/activerecord/lib/active_record/association_relation.rb b/activerecord/lib/active_record/association_relation.rb
index 7bcefe71adbf1..41571857b3281 100644
--- a/activerecord/lib/active_record/association_relation.rb
+++ b/activerecord/lib/active_record/association_relation.rb
@@ -27,6 +27,16 @@ def #{method}(attributes, **kwargs)
       RUBY
     end
 
+    def build(attributes = nil, &block)
+      if attributes.is_a?(Array)
+        attributes.collect { |attr| build(attr, &block) }
+      else
+        block = current_scope_restoring_block(&block)
+        scoping { _new(attributes, &block) }
+      end
+    end
+    alias new build
+
     private
       def _new(attributes, &block)
         @association.build(attributes, &block)
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 9611de60e777e..0fa80319fe788 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -374,14 +374,58 @@ def test_building_the_associated_object_with_an_unrelated_type
     assert_raise(ActiveRecord::SubclassNotFound) { firm.companies.build(type: "Account") }
   end
 
-  test "building the association with an array" do
+  test "build the association with an array" do
     speedometer = Speedometer.new(speedometer_id: "a")
     data = [{ name: "first" }, { name: "second" }]
-    speedometer.minivans.build(data)
+    speedometer.minivans.where(color: "blue").build(data)
 
     assert_equal 2, speedometer.minivans.size
     assert speedometer.save
-    assert_equal ["first", "second"], speedometer.reload.minivans.map(&:name)
+
+    speedometer.reload
+
+    assert_equal ["first", "second"], speedometer.minivans.map(&:name)
+    assert_equal ["blue", "blue"], speedometer.minivans.map(&:color)
+  end
+
+  test "new the association with an array" do
+    speedometer = Speedometer.new(speedometer_id: "a")
+    data = [{ name: "first" }, { name: "second" }]
+    speedometer.minivans.where(color: "blue").new(data)
+
+    assert_equal 2, speedometer.minivans.size
+    assert speedometer.save
+
+    speedometer.reload
+
+    assert_equal ["first", "second"], speedometer.minivans.map(&:name)
+    assert_equal ["blue", "blue"], speedometer.minivans.map(&:color)
+  end
+
+  test "create the association with an array" do
+    speedometer = Speedometer.create!(speedometer_id: "a")
+    data = [{ name: "first" }, { name: "second" }]
+    speedometer.minivans.where(color: "blue").create(data)
+
+    assert_equal 2, speedometer.minivans.size
+
+    speedometer.reload
+
+    assert_equal ["first", "second"], speedometer.minivans.map(&:name)
+    assert_equal ["blue", "blue"], speedometer.minivans.map(&:color)
+  end
+
+  test "create! the association with an array" do
+    speedometer = Speedometer.create!(speedometer_id: "a")
+    data = [{ name: "first" }, { name: "second" }]
+    speedometer.minivans.where(color: "blue").create!(data)
+
+    assert_equal 2, speedometer.minivans.size
+
+    speedometer.reload
+
+    assert_equal ["first", "second"], speedometer.minivans.map(&:name)
+    assert_equal ["blue", "blue"], speedometer.minivans.map(&:color)
   end
 
   def test_association_keys_bypass_attribute_protection