Tests and docs which explain the use of validate with a block and without arguments

2 files changed, 20 insertions, 2 deletions

diff --git a/activemodel/lib/active_model/validations.rb b/activemodel/lib/active_model/validations.rb
index b044caa8d3..6cb015a144 100644
--- a/activemodel/lib/active_model/validations.rb
+++ b/activemodel/lib/active_model/validations.rb
@@ -104,7 +104,7 @@ module ActiveModel
       #     end
       #   end
       #
-      # Or with a block which is passed with the current record to be validated:
+      # With a block which is passed with the current record to be validated:
       #
       #   class Comment
       #     include ActiveModel::Validations
@@ -118,6 +118,16 @@ module ActiveModel
       #     end
       #   end
       #
+      # Or with a block where self points to the current record to be validated:
+      #
+      #   class Comment
+      #     include ActiveModel::Validations
+      #
+      #     validate do
+      #       errors.add(:base, "Must be friends to leave a comment") unless commenter.friend_of?(commentee)
+      #     end
+      #   end
+      #
       def validate(*args, &block)
         options = args.extract_options!
         if options.key?(:on)
diff --git a/activemodel/test/cases/validations_test.rb b/activemodel/test/cases/validations_test.rb
index 55b477dd10..e90dc7d4e3 100644
--- a/activemodel/test/cases/validations_test.rb
+++ b/activemodel/test/cases/validations_test.rb
@@ -148,6 +148,14 @@ class ValidationsTest < ActiveModel::TestCase
   end
 
   def test_validate_block
+    Topic.validate { errors.add("title", "will never be valid") }
+    t = Topic.new("title" => "Title", "content" => "whatever")
+    assert t.invalid?
+    assert t.errors[:title].any?
+    assert_equal ["will never be valid"], t.errors["title"]
+  end
+
+  def test_validate_block_with_params
     Topic.validate { |topic| topic.errors.add("title", "will never be valid") }
     t = Topic.new("title" => "Title", "content" => "whatever")
     assert t.invalid?
@@ -187,7 +195,7 @@ class ValidationsTest < ActiveModel::TestCase
     assert t.invalid?
     assert_equal "can't be blank", t.errors["title"].first
     Topic.validates_presence_of :title, :author_name
-    Topic.validate {|topic| topic.errors.add('author_email_address', 'will never be valid')}
+    Topic.validate {errors.add('author_email_address', 'will never be valid')}
     Topic.validates_length_of :title, :content, :minimum => 2
 
     t = Topic.new :title => ''