3 files changed, 41 insertions, 4 deletions
diff --git a/activemodel/test/cases/dirty_test.rb b/activemodel/test/cases/dirty_test.rb
index 66ed8a350a..d17a12ad12 100644
--- a/activemodel/test/cases/dirty_test.rb
+++ b/activemodel/test/cases/dirty_test.rb
@@ -137,6 +137,19 @@ class DirtyTest < ActiveModel::TestCase
     assert_equal [nil, "Jericho Cane"], @model.previous_changes['name']
   end
 
+  test "setting new attributes should not affect previous changes" do
+    @model.name = "Jericho Cane"
+    @model.save
+    @model.name = "DudeFella ManGuy"
+    assert_equal [nil, "Jericho Cane"], @model.name_previous_change
+  end
+
+  test "saving should preserve model's previous changed status" do
+    @model.name = "Jericho Cane"
+    @model.save
+    assert @model.name_previously_changed?
+  end
+
   test "previous value is preserved when changed after save" do
     assert_equal({}, @model.changed_attributes)
     @model.name = "Paul"
diff --git a/activemodel/test/cases/errors_test.rb b/activemodel/test/cases/errors_test.rb
index da142ea2c0..f781a0017f 100644
--- a/activemodel/test/cases/errors_test.rb
+++ b/activemodel/test/cases/errors_test.rb
@@ -212,6 +212,12 @@ class ErrorsTest < ActiveModel::TestCase
     assert_equal 1, person.errors.size
   end
 
+  test "count calculates the number of error messages" do
+    person = Person.new
+    person.errors.add(:name, "cannot be blank")
+    assert_equal 1, person.errors.count
+  end
+
   test "to_a returns the list of errors with complete messages containing the attribute names" do
     person = Person.new
     person.errors.add(:name, "cannot be blank")
@@ -377,6 +383,12 @@ class ErrorsTest < ActiveModel::TestCase
     assert_empty errors.details[:name]
   end
 
+  test "delete returns the deleted messages" do
+    errors = ActiveModel::Errors.new(Person.new)
+    errors.add(:name, :invalid)
+    assert_equal ["is invalid"], errors.delete(:name)
+  end
+
   test "clear removes details" do
     person = Person.new
     person.errors.add(:name, :invalid)
diff --git a/activemodel/test/cases/validations/length_validation_test.rb b/activemodel/test/cases/validations/length_validation_test.rb
index 209903898e..ee901b75fb 100644
--- a/activemodel/test/cases/validations/length_validation_test.rb
+++ b/activemodel/test/cases/validations/length_validation_test.rb
@@ -319,8 +319,14 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_with_block
-    Topic.validates_length_of :content, minimum: 5, too_short: "Your essay must be at least %{count} words.",
-                                        tokenizer: lambda {|str| str.scan(/\w+/) }
+    assert_deprecated do
+      Topic.validates_length_of(
+        :content,
+        minimum: 5,
+        too_short: "Your essay must be at least %{count} words.",
+        tokenizer: lambda {|str| str.scan(/\w+/) },
+      )
+    end
     t = Topic.new(content: "this content should be long enough")
     assert t.valid?
 
@@ -332,8 +338,14 @@ class LengthValidationTest < ActiveModel::TestCase
 
 
   def test_validates_length_of_with_symbol
-    Topic.validates_length_of :content, minimum: 5, too_short: "Your essay must be at least %{count} words.",
-                                        tokenizer: :my_word_tokenizer
+    assert_deprecated do
+      Topic.validates_length_of(
+        :content,
+        minimum: 5,
+        too_short: "Your essay must be at least %{count} words.",
+        tokenizer: :my_word_tokenizer,
+      )
+    end
     t = Topic.new(content: "this content should be long enough")
     assert t.valid?