1 files changed, 49 insertions, 0 deletions
diff --git a/activemodel/test/cases/errors_test.rb b/activemodel/test/cases/errors_test.rb
index baaf404f2e..d66d6ceff0 100644
--- a/activemodel/test/cases/errors_test.rb
+++ b/activemodel/test/cases/errors_test.rb
@@ -274,6 +274,28 @@ class ErrorsTest < ActiveModel::TestCase
     assert_equal [msg], person.errors[:name]
   end
 
+  test "added? when attribute was added through a collection" do
+    person = Person.new
+    person.errors.add(:"family_members.name", :too_long, count: 25)
+    assert person.errors.added?(:"family_members.name", :too_long, count: 25)
+    assert_not person.errors.added?(:"family_members.name", :too_long)
+    assert_not person.errors.added?(:"family_members.name", :too_long, name: "hello")
+  end
+
+  test "added? ignores callback option" do
+    person = Person.new
+
+    person.errors.add(:name, :too_long, if: -> { true })
+    assert person.errors.added?(:name, :too_long)
+  end
+
+  test "added? ignores message option" do
+    person = Person.new
+
+    person.errors.add(:name, :too_long, message: proc { "foo" })
+    assert person.errors.added?(:name, :too_long)
+  end
+
   test "added? detects indifferent if a specific error was added to the object" do
     person = Person.new
     person.errors.add(:name, "cannot be blank")
@@ -460,6 +482,27 @@ class ErrorsTest < ActiveModel::TestCase
     assert_nil person.errors.as_json.default_proc
   end
 
+  test "full_messages doesn't require the base object to respond to `:errors" do
+    model = Class.new do
+      def initialize
+        @errors = ActiveModel::Errors.new(self)
+        @errors.add(:name, "bar")
+      end
+
+      def self.human_attribute_name(attr, options = {})
+        "foo"
+      end
+
+      def call
+        error_wrapper = Struct.new(:model_errors)
+
+        error_wrapper.new(@errors)
+      end
+    end
+
+    assert_equal(["foo bar"], model.new.call.model_errors.full_messages)
+  end
+
   test "full_messages creates a list of error messages with the attribute name included" do
     person = Person.new
     person.errors.add(:name, "cannot be blank")
@@ -573,6 +616,12 @@ class ErrorsTest < ActiveModel::TestCase
     assert_not_equal errors_dup.details, errors.details
   end
 
+  test "delete returns nil when no errors were deleted" do
+    errors = ActiveModel::Errors.new(Person.new)
+
+    assert_nil(errors.delete(:name))
+  end
+
   test "delete removes details on given attribute" do
     errors = ActiveModel::Errors.new(Person.new)
     errors.add(:name, :invalid)