1 files changed, 83 insertions, 0 deletions
diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index 3bd8475bb0..0e58e65a07 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -726,6 +726,89 @@ class DirtyTest < ActiveRecord::TestCase
     assert person.changed?
   end
 
+  test "saved_change_to_attribute? returns whether a change occurred in the last save" do
+    person = Person.create!(first_name: "Sean")
+
+    assert person.saved_change_to_first_name?
+    refute person.saved_change_to_gender?
+    assert person.saved_change_to_first_name?(from: nil, to: "Sean")
+    assert person.saved_change_to_first_name?(from: nil)
+    assert person.saved_change_to_first_name?(to: "Sean")
+    refute person.saved_change_to_first_name?(from: "Jim", to: "Sean")
+    refute person.saved_change_to_first_name?(from: "Jim")
+    refute person.saved_change_to_first_name?(to: "Jim")
+  end
+
+  test "saved_change_to_attribute returns the change that occurred in the last save" do
+    person = Person.create!(first_name: "Sean", gender: "M")
+
+    assert_equal [nil, "Sean"], person.saved_change_to_first_name
+    assert_equal [nil, "M"], person.saved_change_to_gender
+
+    person.update(first_name: "Jim")
+
+    assert_equal ["Sean", "Jim"], person.saved_change_to_first_name
+    assert_nil person.saved_change_to_gender
+  end
+
+  test "attribute_before_last_save returns the original value before saving" do
+    person = Person.create!(first_name: "Sean", gender: "M")
+
+    assert_nil person.first_name_before_last_save
+    assert_nil person.gender_before_last_save
+
+    person.first_name = "Jim"
+
+    assert_nil person.first_name_before_last_save
+    assert_nil person.gender_before_last_save
+
+    person.save
+
+    assert_equal "Sean", person.first_name_before_last_save
+    assert_equal "M", person.gender_before_last_save
+  end
+
+  test "saved_changes? returns whether the last call to save changed anything" do
+    person = Person.create!(first_name: "Sean")
+
+    assert person.saved_changes?
+
+    person.save
+
+    refute person.saved_changes?
+  end
+
+  test "saved_changes returns a hash of all the changes that occurred" do
+    person = Person.create!(first_name: "Sean", gender: "M")
+
+    assert_equal [nil, "Sean"], person.saved_changes[:first_name]
+    assert_equal [nil, "M"], person.saved_changes[:gender]
+    assert_equal %w(id first_name gender created_at updated_at).sort, person.saved_changes.keys.sort
+
+    travel(1.second) do
+      person.update(first_name: "Jim")
+    end
+
+    assert_equal ["Sean", "Jim"], person.saved_changes[:first_name]
+    assert_equal %w(first_name lock_version updated_at).sort, person.saved_changes.keys.sort
+  end
+
+  test "changed? in after callbacks returns true but is deprecated" do
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = "people"
+
+      after_save do
+        ActiveSupport::Deprecation.silence do
+          raise "changed? should be true" unless changed?
+        end
+        raise "has_changes_to_save? should be false" if has_changes_to_save?
+      end
+    end
+
+    person = klass.create!(first_name: "Sean")
+    refute person.changed?
+  end
+
   private
     def with_partial_writes(klass, on = true)
       old = klass.partial_writes?