1 files changed, 12 insertions, 0 deletions
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)