7 files changed, 15 insertions, 8 deletions
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 6882b59e26..c82d4f012c 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -308,7 +308,7 @@ module ActiveModel
     #   person.errors.messages
     #   # => {:name=>["can't be empty"]}
     def add_on_empty(attributes, options = {})
-      [attributes].flatten.each do |attribute|
+      Array(attributes).each do |attribute|
         value = @base.send(:read_attribute_for_validation, attribute)
         is_empty = value.respond_to?(:empty?) ? value.empty? : false
         add(attribute, :empty, options) if value.nil? || is_empty
@@ -322,7 +322,7 @@ module ActiveModel
     #   person.errors.messages
     #   # => {:name=>["can't be blank"]}
     def add_on_blank(attributes, options = {})
-      [attributes].flatten.each do |attribute|
+      Array(attributes).each do |attribute|
         value = @base.send(:read_attribute_for_validation, attribute)
         add(attribute, :blank, options) if value.blank?
       end
diff --git a/activemodel/lib/active_model/forbidden_attributes_protection.rb b/activemodel/lib/active_model/forbidden_attributes_protection.rb
index 4c05b19cba..7468f95548 100644
--- a/activemodel/lib/active_model/forbidden_attributes_protection.rb
+++ b/activemodel/lib/active_model/forbidden_attributes_protection.rb
@@ -16,7 +16,7 @@ module ActiveModel
 
   module ForbiddenAttributesProtection # :nodoc:
     protected
-      def sanitize_for_mass_assignment(attributes, options = {})
+      def sanitize_for_mass_assignment(attributes)
         if attributes.respond_to?(:permitted?) && !attributes.permitted?
           raise ActiveModel::ForbiddenAttributesError
         else
diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index eb8265d8c6..264880eecd 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -263,10 +263,10 @@ module ActiveModel
     # namespaced models regarding whether it's inside isolated engine.
     #
     #   # For isolated engine:
-    #   ActiveModel::Naming.route_key(Blog::Post) #=> post
+    #   ActiveModel::Naming.singular_route_key(Blog::Post) #=> post
     #
     #   # For shared engine:
-    #   ActiveModel::Naming.route_key(Blog::Post) #=> blog_post
+    #   ActiveModel::Naming.singular_route_key(Blog::Post) #=> blog_post
     def self.singular_route_key(record_or_class)
       model_name_from_record_or_class(record_or_class).singular_route_key
     end
diff --git a/activemodel/lib/active_model/railtie.rb b/activemodel/lib/active_model/railtie.rb
index 75cde900e3..1671eb7bd4 100644
--- a/activemodel/lib/active_model/railtie.rb
+++ b/activemodel/lib/active_model/railtie.rb
@@ -4,5 +4,9 @@ require "rails"
 module ActiveModel
   class Railtie < Rails::Railtie # :nodoc:
     config.eager_load_namespaces << ActiveModel
+
+    initializer "active_model.secure_password" do
+      ActiveModel::SecurePassword.min_cost = Rails.env.test?
+    end
   end
 end
diff --git a/activemodel/lib/active_model/secure_password.rb b/activemodel/lib/active_model/secure_password.rb
index f19c836bea..081a49f749 100644
--- a/activemodel/lib/active_model/secure_password.rb
+++ b/activemodel/lib/active_model/secure_password.rb
@@ -2,6 +2,8 @@ module ActiveModel
   module SecurePassword
     extend ActiveSupport::Concern
 
+    class << self; attr_accessor :min_cost; end
+
     module ClassMethods
       # Adds methods to set and authenticate against a BCrypt password.
       # This mechanism requires you to have a password_digest attribute.
@@ -92,7 +94,8 @@ module ActiveModel
       def password=(unencrypted_password)
         unless unencrypted_password.blank?
           @password = unencrypted_password
-          self.password_digest = BCrypt::Password.create(unencrypted_password)
+          cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST : BCrypt::Engine::DEFAULT_COST
+          self.password_digest = BCrypt::Password.create(unencrypted_password, cost: cost)
         end
       end
     end
diff --git a/activemodel/lib/active_model/validations/validates.rb b/activemodel/lib/active_model/validations/validates.rb
index 4651154934..1eb0716891 100644
--- a/activemodel/lib/active_model/validations/validates.rb
+++ b/activemodel/lib/active_model/validations/validates.rb
@@ -104,7 +104,7 @@ module ActiveModel
         raise ArgumentError, "You need to supply at least one attribute" if attributes.empty?
         raise ArgumentError, "You need to supply at least one validation" if validations.empty?
 
-        defaults.merge!(:attributes => attributes)
+        defaults[:attributes] = attributes
 
         validations.each do |key, options|
           next unless options
diff --git a/activemodel/lib/active_model/validator.rb b/activemodel/lib/active_model/validator.rb
index c795dc9dcd..629b157fed 100644
--- a/activemodel/lib/active_model/validator.rb
+++ b/activemodel/lib/active_model/validator.rb
@@ -135,7 +135,7 @@ module ActiveModel
     # and instead be made available through the +attributes+ reader.
     def initialize(options)
       @attributes = Array(options.delete(:attributes))
-      raise ":attributes cannot be blank" if @attributes.empty?
+      raise ArgumentError, ":attributes cannot be blank" if @attributes.empty?
       super
       check_validity!
     end