1 files changed, 33 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/nested_error.rb b/activemodel/lib/active_model/nested_error.rb
new file mode 100644
index 0000000000..93348c7771
--- /dev/null
+++ b/activemodel/lib/active_model/nested_error.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require "active_model/error"
+require "forwardable"
+
+module ActiveModel
+  # Represents one single error
+  # @!attribute [r] base
+  #   @return [ActiveModel::Base] the object which the error belongs to
+  # @!attribute [r] attribute
+  #   @return [Symbol] attribute of the object which the error belongs to
+  # @!attribute [r] type
+  #   @return [Symbol] error's type
+  # @!attribute [r] options
+  #   @return [Hash] additional options
+  # @!attribute [r] inner_error
+  #   @return [Error] inner error
+  class NestedError < Error
+    def initialize(base, inner_error, override_options = {})
+      @base = base
+      @inner_error = inner_error
+      @attribute = override_options.fetch(:attribute) { inner_error.attribute }
+      @type = override_options.fetch(:type) { inner_error.type }
+      @raw_type = inner_error.raw_type
+      @options = inner_error.options
+    end
+
+    attr_reader :inner_error
+
+    extend Forwardable
+    def_delegators :@inner_error, :message
+  end
+end