1 files changed, 90 insertions, 5 deletions

diff --git a/activemodel/lib/active_model/error.rb b/activemodel/lib/active_model/error.rb
index f7267fc7bf..6deab3578d 100644
--- a/activemodel/lib/active_model/error.rb
+++ b/activemodel/lib/active_model/error.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "active_support/core_ext/class/attribute"
+
 module ActiveModel
   # == Active \Model \Error
   #
@@ -8,6 +10,89 @@ module ActiveModel
     CALLBACKS_OPTIONS = [:if, :unless, :on, :allow_nil, :allow_blank, :strict]
     MESSAGE_OPTIONS = [:message]
 
+    class_attribute :i18n_customize_full_message, default: false
+
+    def self.full_message(attribute, message, base_class) # :nodoc:
+      return message if attribute == :base
+      attribute = attribute.to_s
+
+      if i18n_customize_full_message && base_class.respond_to?(:i18n_scope)
+        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"
+
+        if namespace
+          defaults = base_class.lookup_ancestors.map do |klass|
+            [
+              :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.attributes.#{attribute_name}.format",
+              :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.format",
+            ]
+          end
+        else
+          defaults = base_class.lookup_ancestors.map do |klass|
+            [
+              :"#{attributes_scope}.#{klass.model_name.i18n_key}.attributes.#{attribute_name}.format",
+              :"#{attributes_scope}.#{klass.model_name.i18n_key}.format",
+            ]
+          end
+        end
+
+        defaults.flatten!
+      else
+        defaults = []
+      end
+
+      defaults << :"errors.format"
+      defaults << "%{attribute} %{message}"
+
+      attr_name = attribute.tr(".", "_").humanize
+      attr_name = base_class.human_attribute_name(attribute, default: attr_name)
+
+      I18n.t(defaults.shift,
+        default:  defaults,
+        attribute: attr_name,
+        message:   message)
+    end
+
+    def self.generate_message(attribute, type, base, options) # :nodoc:
+      type = options.delete(:message) if options[:message].is_a?(Symbol)
+      value = (attribute != :base ? base.send(:read_attribute_for_validation, attribute) : nil)
+
+      options = {
+        model: base.model_name.human,
+        attribute: base.class.human_attribute_name(attribute),
+        value: value,
+        object: base
+      }.merge!(options)
+
+      if base.class.respond_to?(:i18n_scope)
+        i18n_scope = base.class.i18n_scope.to_s
+        defaults = base.class.lookup_ancestors.flat_map do |klass|
+          [ :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.attributes.#{attribute}.#{type}",
+            :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.#{type}" ]
+        end
+        defaults << :"#{i18n_scope}.errors.messages.#{type}"
+
+        catch(:exception) do
+          translation = I18n.translate(defaults.first, options.merge(default: defaults.drop(1), throw: true))
+          return translation unless translation.nil?
+        end unless options[:message]
+      else
+        defaults = []
+      end
+
+      defaults << :"errors.attributes.#{attribute}.#{type}"
+      defaults << :"errors.messages.#{type}"
+
+      key = defaults.shift
+      defaults = options.delete(:message) if options[:message]
+      options[:default] = defaults
+
+      I18n.translate(key, options)
+    end
+
     def initialize(base, attribute, type = :invalid, **options)
       @base = base
       @attribute = attribute
@@ -28,7 +113,7 @@ module ActiveModel
     def message
       case raw_type
       when Symbol
-        base.errors.generate_message(attribute, raw_type, options.except(*CALLBACKS_OPTIONS))
+        self.class.generate_message(attribute, raw_type, @base, options.except(*CALLBACKS_OPTIONS))
       else
         raw_type
       end
@@ -39,7 +124,7 @@ module ActiveModel
     end
 
     def full_message
-      base.errors.full_message(attribute, message)
+      self.class.full_message(attribute, message, @base.class)
     end
 
     # See if error matches provided +attribute+, +type+ and +options+.
@@ -58,9 +143,9 @@ module ActiveModel
     end
 
     def strict_match?(attribute, type, **options)
-      return false unless match?(attribute, type, **options)
+      return false unless match?(attribute, type)
 
-      full_message == Error.new(@base, attribute, type, **options).full_message
+      options == @options.except(*CALLBACKS_OPTIONS + MESSAGE_OPTIONS)
     end
 
     def ==(other)
@@ -74,7 +159,7 @@ module ActiveModel
 
     protected
       def attributes_for_hash
-        [@base, @attribute, @raw_type, @options]
+        [@base, @attribute, @raw_type, @options.except(*CALLBACKS_OPTIONS)]
       end
   end
 end