1 files changed, 15 insertions, 0 deletions
diff --git a/activemodel/test/cases/errors_test.rb b/activemodel/test/cases/errors_test.rb
index 8ddedb160a..e2dea12589 100644
--- a/activemodel/test/cases/errors_test.rb
+++ b/activemodel/test/cases/errors_test.rb
@@ -27,6 +27,13 @@ class ErrorsTest < ActiveModel::TestCase
     end
   end
 
+  def test_delete
+    errors = ActiveModel::Errors.new(self)
+    errors[:foo] = 'omg'
+    errors.delete(:foo)
+    assert errors[:foo].empty?
+  end
+
   def test_include?
     errors = ActiveModel::Errors.new(self)
     errors[:foo] = 'omg'
@@ -39,6 +46,14 @@ class ErrorsTest < ActiveModel::TestCase
     assert errors.has_key?(:foo), 'errors should have key :foo'
   end
 
+  def test_dup
+    errors = ActiveModel::Errors.new(self)
+    errors[:foo] = 'bar'
+    errors_dup = errors.dup
+    errors_dup[:bar] = 'omg'
+    assert_not_same errors_dup.messages, errors.messages
+  end
+
   test "should return true if no errors" do
     person = Person.new
     person.errors[:foo]