`ActiveModel.full_message` interaction with `index_errors`

2 files changed, 63 insertions, 3 deletions

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index edc30ee64d..5138a07b71 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -379,9 +379,11 @@ module ActiveModel
     # * <tt>errors.format</tt>
     def full_message(attribute, message)
       return message if attribute == :base
+      attribute = attribute.to_s
 
       if self.class.i18n_full_message && @base.class.respond_to?(:i18n_scope)
-        parts = attribute.to_s.split(".")
+        attribute = attribute.remove(/\[\d\]/)
+        parts = attribute.split(".")
         attribute_name = parts.pop
         namespace = parts.join("/") unless parts.empty?
         attributes_scope = "#{@base.class.i18n_scope}.errors.models"
@@ -410,8 +412,9 @@ module ActiveModel
       defaults << :"errors.format"
       defaults << "%{attribute} %{message}"
 
-      attr_name = attribute.to_s.tr(".", "_").humanize
-      attr_name = @base.class.human_attribute_name(attribute, default: attr_name)
+      attr_name = attribute.tr(".", "_").humanize
+      attr_name = @base.class.human_attribute_name(attribute.to_sym, default: attr_name)
+
       I18n.t(defaults.shift,
         default:  defaults,
         attribute: attr_name,
diff --git a/activemodel/test/cases/validations/i18n_validation_test.rb b/activemodel/test/cases/validations/i18n_validation_test.rb
index 1c62e750de..3e135e6f8e 100644
--- a/activemodel/test/cases/validations/i18n_validation_test.rb
+++ b/activemodel/test/cases/validations/i18n_validation_test.rb
@@ -101,6 +101,63 @@ class I18nValidationTest < ActiveModel::TestCase
     assert_equal "cannot be blank", person.errors.full_message(:'contacts/addresses.country', "cannot be blank")
   end
 
+  def test_errors_full_messages_with_indexed_deeply_nested_attributes_and_attributes_format
+    ActiveModel::Errors.i18n_full_message = true
+
+    I18n.backend.store_translations("en", activemodel: {
+      errors: { models: { 'person/contacts/addresses': { attributes: { street: { format: "%{message}" } } } } } })
+
+    person = Person.new
+    assert_equal "cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].street', "cannot be blank")
+    assert_equal "Contacts/addresses country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].country', "cannot be blank")
+  end
+
+  def test_errors_full_messages_with_indexed_deeply_nested_attributes_and_model_format
+    ActiveModel::Errors.i18n_full_message = true
+
+    I18n.backend.store_translations("en", activemodel: {
+      errors: { models: { 'person/contacts/addresses': { format: "%{message}" } } } })
+
+    person = Person.new
+    assert_equal "cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].street', "cannot be blank")
+    assert_equal "cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].country', "cannot be blank")
+  end
+
+  def test_errors_full_messages_with_indexed_deeply_nested_attributes_and_i18n_attribute_name
+    ActiveModel::Errors.i18n_full_message = true
+
+    I18n.backend.store_translations("en", activemodel: {
+      attributes: { 'person/contacts/addresses': { country: "Country" } }
+    })
+
+    person = Person.new
+    assert_equal "Contacts/addresses street cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].street', "cannot be blank")
+    assert_equal "Country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].country', "cannot be blank")
+  end
+
+  def test_errors_full_messages_with_indexed_deeply_nested_attributes_without_i18n_config
+    ActiveModel::Errors.i18n_full_message = false
+
+    I18n.backend.store_translations("en", activemodel: {
+      errors: { models: { 'person/contacts/addresses': { attributes: { street: { format: "%{message}" } } } } } })
+
+    person = Person.new
+    assert_equal "Contacts[0]/addresses[0] street cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].street', "cannot be blank")
+    assert_equal "Contacts[0]/addresses[0] country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].country', "cannot be blank")
+  end
+
+  def test_errors_full_messages_with_i18n_attribute_name_without_i18n_config
+    ActiveModel::Errors.i18n_full_message = false
+
+    I18n.backend.store_translations("en", activemodel: {
+      attributes: { 'person/contacts[0]/addresses[0]': { country: "Country" } }
+    })
+
+    person = Person.new
+    assert_equal "Contacts[0]/addresses[0] street cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].street', "cannot be blank")
+    assert_equal "Country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].country', "cannot be blank")
+  end
+
   # ActiveModel::Validations
 
   # A set of common cases for ActiveModel::Validations message generation that