4 files changed, 30 insertions, 17 deletions
diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index 6591d50d06..d2d8ea8042 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -120,6 +120,16 @@ class PostgresqlUUIDTest < ActiveRecord::PostgreSQLTestCase
     assert_empty UUIDType.where(guid: "foobar")
   end
 
+  class DuckUUID
+    def initialize(uuid)
+      @uuid = uuid
+    end
+
+    def to_s
+      @uuid
+    end
+  end
+
   def test_acceptable_uuid_regex
     # Valid uuids
     ["A0EEBC99-9C0B-4EF8-BB6D-6BB9BD380A11",
@@ -131,9 +141,11 @@ class PostgresqlUUIDTest < ActiveRecord::PostgreSQLTestCase
      # so we shouldn't block it either. (Pay attention to "fb6d" – the "f" here
      # is invalid – it must be one of 8, 9, A, B, a, b according to the spec.)
      "{a0eebc99-9c0b-4ef8-fb6d-6bb9bd380a11}",
+     # Support Object-Oriented UUIDs which respond to #to_s
+     DuckUUID.new("A0EEBC99-9C0B-4EF8-BB6D-6BB9BD380A11"),
     ].each do |valid_uuid|
       uuid = UUIDType.new guid: valid_uuid
-      assert_not_nil uuid.guid
+      assert_instance_of String, uuid.guid
     end
 
     # Invalid uuids
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index 63528d09d5..866818b2ab 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -1055,23 +1055,23 @@ class BasicsTest < ActiveRecord::TestCase
   end
 
   def test_find_ordered_last
-    last = Developer.all.merge!(order: "developers.salary ASC").last
-    assert_equal last, Developer.all.merge!(order: "developers.salary ASC").to_a.last
+    last = Developer.order("developers.salary ASC").last
+    assert_equal last, Developer.order("developers.salary": "ASC").to_a.last
   end
 
   def test_find_reverse_ordered_last
-    last = Developer.all.merge!(order: "developers.salary DESC").last
-    assert_equal last, Developer.all.merge!(order: "developers.salary DESC").to_a.last
+    last = Developer.order("developers.salary DESC").last
+    assert_equal last, Developer.order("developers.salary": "DESC").to_a.last
   end
 
   def test_find_multiple_ordered_last
-    last = Developer.all.merge!(order: "developers.name, developers.salary DESC").last
-    assert_equal last, Developer.all.merge!(order: "developers.name, developers.salary DESC").to_a.last
+    last = Developer.order("developers.name, developers.salary DESC").last
+    assert_equal last, Developer.order(:"developers.name", "developers.salary": "DESC").to_a.last
   end
 
   def test_find_keeps_multiple_order_values
-    combined = Developer.all.merge!(order: "developers.name, developers.salary").to_a
-    assert_equal combined, Developer.all.merge!(order: ["developers.name", "developers.salary"]).to_a
+    combined = Developer.order("developers.name, developers.salary").to_a
+    assert_equal combined, Developer.order(:"developers.name", :"developers.salary").to_a
   end
 
   def test_find_keeps_multiple_group_values
diff --git a/activerecord/test/models/topic.rb b/activerecord/test/models/topic.rb
index 75890c327a..0c8880a20e 100644
--- a/activerecord/test/models/topic.rb
+++ b/activerecord/test/models/topic.rb
@@ -99,7 +99,7 @@ class Topic < ActiveRecord::Base
     end
 
     def destroy_children
-      self.class.where("parent_id = #{id}").delete_all
+      self.class.delete_by(parent_id: id)
     end
 
     def set_email_address
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 349b8afc48..1dfea0f506 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -94,17 +94,18 @@ ActiveRecord::Schema.define do
   end
 
   create_table :books, id: :integer, force: true do |t|
+    default_zero = { default: 0 }
     t.references :author
     t.string :format
     t.column :name, :string
-    t.column :status, :integer, default: 0
-    t.column :read_status, :integer, default: 0
+    t.column :status, :integer, **default_zero
+    t.column :read_status, :integer, **default_zero
     t.column :nullable_status, :integer
-    t.column :language, :integer, default: 0
-    t.column :author_visibility, :integer, default: 0
-    t.column :illustrator_visibility, :integer, default: 0
-    t.column :font_size, :integer, default: 0
-    t.column :difficulty, :integer, default: 0
+    t.column :language, :integer, **default_zero
+    t.column :author_visibility, :integer, **default_zero
+    t.column :illustrator_visibility, :integer, **default_zero
+    t.column :font_size, :integer, **default_zero
+    t.column :difficulty, :integer, **default_zero
     t.column :cover, :string, default: "hard"
   end