Validation Assertions

Posted by John Wulff Tue, 26 Jun 2007 19:06:00 GMT

I like to test my validations. While I don’t really care to test the underlying code that runs the validations (I trust the Rails team to make sure they work as advertised) I do like the reassurance that I didn’t screw up. So, I’ve written this small plugin to help me test my validations.

It works simply. In one of your models you’ve got a validation like this: 
class User < ActiveRecord::Base
  validates_presence_of :name
  validates_length_of :name, :in => 4..26
  validates_uniqueness_of :name
end
To test the validations: 
class UserTest < Test::Unit::TestCase  
  # Assert that a User's name must exist for validations to pass.
  def test_validates_presence_of_name
    assert_validates_presence_of User, :name
  end

  # Assert that a User's name must be at least 4 characters in length for
  # validations to pass.
  def test_validates_minimium_length_of_name
    assert_validates_minimum_length_of User, :name, 4
  end

  # Assert that a User's name must be less than 26 characters in length for
  # validations to pass.
  def test_validates_maximum_length_of_name
    assert_validates_maximum_length_of User, :name, 26
  end

  # Assert that a User's name must be unique for validations to pass.
  def test_validates_uniqueness_of_name
    assert_validates_uniqueness_of User, :name
  end
end

That’s it. Now you can rest easy know that your validations are really, really, really in place.

To install the plugin: 
script/plugin install http://validation-assertions.googlecode.com/svn/trunk/validation_assertions/

Google Code Project Page

XML Validation Plugin

Posted by John Wulff Wed, 04 Oct 2006 03:19:00 GMT

I’ve written a new Rails plugin to validate xml.

class Article < ActiveRecord::Base
  validates_xml :body
end
Then 
Article.new(:body => "<span>This will fail").save!
will throw 
ActiveRecord::RecordInvalid: Validation failed: Body is not valid xml

Get it here: https://secure.near-time.com/svn/plugins/trunk/validates_xml

Rails validates_presence_of Strangeness

Posted by John Wulff Tue, 16 May 2006 02:53:00 GMT

I found an annoying bug in validates_presence_of, it does not like booleans.

class CreateNodes < ActiveRecord::Migration
  def self.up
    create_table :nodes do |t|
      t.column :boolean_var, :boolean, :default => 0
    end
  end
end
class Node < ActiveRecord::Base
  validates_presence_of :boolean_var
end
class NodeTest < Test::Unit::TestCase
  def test_boolean_var
    node = Node.new
    node.boolean_var = 0
    node.save!
  end
end
  1) Error:
 test_boolean_var(NodeTest):
 ActiveRecord::RecordInvalid: Validation failed: Boolean var can't be blank
 /opt/local/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/validations.rb:736:in
 `save!'
    /Users/jwulff/Development/NodeTestApp/test/unit/node_test.rb:5:in
 `test_boolean_var'

 1 tests, 0 assertions, 0 failures, 1 errors

Blake Watters gave me this workaround.

validates_inclusion_of :boolean_var, :in => [true, false]

I’ve opened a ticket at dev.rubyonrails.org

UPDATE: The ticket has been closed as invalid. Manfred says:

validates_presence_of behaves exactly as documented. Please use {{{validates_inclusion_of :boolean_var, :in => [true, false]}} as the first commenter suggested.