4 files changed, 21 insertions, 19 deletions
diff --git a/activemodel/lib/active_model.rb b/activemodel/lib/active_model.rb
index 58fe08cc11..8aa1b6f664 100644
--- a/activemodel/lib/active_model.rb
+++ b/activemodel/lib/active_model.rb
@@ -50,6 +50,7 @@ module ActiveModel
   eager_autoload do
     autoload :Errors
     autoload :StrictValidationFailed, 'active_model/errors'
+    autoload :UnknownAttributeError, 'active_model/errors'
   end
 
   module Serializers
diff --git a/activemodel/lib/active_model/attribute_assignment.rb b/activemodel/lib/active_model/attribute_assignment.rb
index 356421476c..087d11f708 100644
--- a/activemodel/lib/active_model/attribute_assignment.rb
+++ b/activemodel/lib/active_model/attribute_assignment.rb
@@ -48,16 +48,5 @@ module ActiveModel
         raise UnknownAttributeError.new(self, k)
       end
     end
-
-    # Raised when unknown attributes are supplied via mass assignment.
-    class UnknownAttributeError < NoMethodError
-      attr_reader :record, :attribute
-
-      def initialize(record, attribute)
-        @record = record
-        @attribute = attribute
-        super("unknown attribute '#{attribute}' for #{@record.class}.")
-      end
-    end
   end
 end
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 8326853879..e35ed03e74 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -3,6 +3,7 @@
 require 'active_support/core_ext/array/conversions'
 require 'active_support/core_ext/string/inflections'
 require 'active_support/core_ext/object/deep_dup'
+require 'active_support/core_ext/string/filters'
 
 module ActiveModel
   # == Active \Model \Errors
@@ -33,11 +34,11 @@ module ActiveModel
   #       send(attr)
   #     end
   #
-  #     def Person.human_attribute_name(attr, options = {})
+  #     def self.human_attribute_name(attr, options = {})
   #       attr
   #     end
   #
-  #     def Person.lookup_ancestors
+  #     def self.lookup_ancestors
   #       [self]
   #     end
   #   end
@@ -123,9 +124,9 @@ module ActiveModel
 
     # Set messages for +key+ to +value+.
     #
-    #   person.errors.get(:name) # => ["cannot be nil"]
+    #   person.errors[:name] # => ["cannot be nil"]
     #   person.errors.set(:name, ["can't be nil"])
-    #   person.errors.get(:name) # => ["can't be nil"]
+    #   person.errors[:name] # => ["can't be nil"]
     def set(key, value)
       ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
         ActiveModel::Errors#set is deprecated and will be removed in Rails 5.1.
@@ -138,12 +139,12 @@ module ActiveModel
 
     # Delete messages for +key+. Returns the deleted messages.
     #
-    #   person.errors.get(:name)    # => ["cannot be nil"]
+    #   person.errors[:name]    # => ["cannot be nil"]
     #   person.errors.delete(:name) # => ["cannot be nil"]
-    #   person.errors.get(:name)    # => []
+    #   person.errors[:name]    # => []
     def delete(key)
-      messages.delete(key)
       details.delete(key)
+      messages.delete(key)
     end
 
     # When passed a symbol or a name of a method, returns an array of errors
@@ -524,4 +525,15 @@ module ActiveModel
   #   # => ActiveModel::StrictValidationFailed: Name can't be blank
   class StrictValidationFailed < StandardError
   end
+
+  # Raised when unknown attributes are supplied via mass assignment.
+  class UnknownAttributeError < NoMethodError
+    attr_reader :record, :attribute
+
+    def initialize(record, attribute)
+      @record = record
+      @attribute = attribute
+      super("unknown attribute '#{attribute}' for #{@record.class}.")
+    end
+  end
 end
diff --git a/activemodel/lib/active_model/secure_password.rb b/activemodel/lib/active_model/secure_password.rb
index 871031ece4..89da74efa8 100644
--- a/activemodel/lib/active_model/secure_password.rb
+++ b/activemodel/lib/active_model/secure_password.rb
@@ -26,7 +26,7 @@ module ActiveModel
       # it). When this attribute has a +nil+ value, the validation will not be
       # triggered.
       #
-      # For further customizability, it is possible to supress the default
+      # For further customizability, it is possible to suppress the default
       # validations by passing <tt>validations: false</tt> as an argument.
       #
       # Add bcrypt (~> 3.1.7) to Gemfile to use #has_secure_password: