Allow checking whether an attribute previously changed from/to a particular value

activemodel/CHANGELOG.md

@@ -1,3 +1,11 @@
+*   `*_previously_changed?` accepts `:from` and `:to` keyword arguments like `*_changed?`.
+
+        topic.update!(status: :archived)
+        topic.status_previously_changed?(from: "active", to: "archived")
+        # => true
+
+    *George Claghorn*
+
 *   Raise FrozenError when trying to write attributes that aren't backed by the database on an object that is frozen:
 
         class Animal

activemodel/lib/active_model/dirty.rb

@@ -83,6 +83,7 @@ module ActiveModel
   #
   #   person.previous_changes         # => {"name" => [nil, "Bill"]}
   #   person.name_previously_changed? # => true
+  #   person.name_previously_changed?(from: nil, to: "Bill") # => true
   #   person.name_previous_change     # => [nil, "Bill"]
   #   person.name_previously_was      # => nil
   #   person.reload!
@@ -177,8 +178,8 @@ module ActiveModel
     end
 
     # Dispatch target for <tt>*_previously_changed?</tt> attribute methods.
-    def attribute_previously_changed?(attr_name) # :nodoc:
+    def attribute_previously_changed?(attr_name, **options) # :nodoc:
-      mutations_before_last_save.changed?(attr_name.to_s)
+      mutations_before_last_save.changed?(attr_name.to_s, **options)
     end
 
     # Dispatch target for <tt>*_previously_was</tt> attribute methods.

activemodel/test/cases/dirty_test.rb

@@ -149,6 +149,17 @@ class DirtyTest < ActiveModel::TestCase
     assert_predicate @model, :name_previously_changed?
   end
 
+  test "checking if an attribute was previously changed to a particular value" do
+    @model.name = "Ringo"
+    @model.save
+    assert @model.name_previously_changed?(from: nil, to: "Ringo")
+    assert_not @model.name_previously_changed?(from: "Pete", to: "Ringo")
+    assert @model.name_previously_changed?(to: "Ringo")
+    assert_not @model.name_previously_changed?(to: "Pete")
+    assert @model.name_previously_changed?(from: nil)
+    assert_not @model.name_previously_changed?(from: "Pete")
+  end
+
   test "previous value is preserved when changed after save" do
     assert_equal({}, @model.changed_attributes)
     @model.name = "Paul"