==== it "should use a dummy method with argument and return value" do dummy = mock("dummy").stub!(:emulate) dummy.should_receive(:emulate).with(:something).and_return("Done! sir!") dummy.emulate(:something).should == "Done! sir!" end

I don't think this is mentioned in the docs anywhere, or else I couldn't find it: Because validate, validate_on_create, and validate_on_update are ActiveSupport::Callbacks, their symbol forms support conditions just like validates_presence_of and company:

validate :permaname_must_be_unique, :if...

When you're trying to construct a specialized path name for a partial based on a record type you're probably better off writing your own helper.

def topic_partial_path(topic)
['admin', topic.class.table_name, "#{topic.class.table_name.singularize}_as_topic"].join('/')
end

If your controllers are redirecting more than once, the flash contents will be lost. To avoid it, execute flash.keep before each redirection.

Check ActionController::Flash::FlashHash for more handy methods (discard, now, ...)

Checkout with_exclusive_scope

=== Code example Article.with_exclusive_scope { find(:all) } #=> "SELECT * FROM 'articles'

from http://ryandaigle.com/articles/2008/11/18/what-s-new-in-edge-rails-default-scoping

Correct way is this:

[:a, :b, :c].try(:at, 1)

$! The exception information message set by 'raise'. $@ Array of backtrace of the last exception thrown.

$&         The string matched by the last successful pattern match in this scope.
$`         The string to the left  of the last successful match.
$'         The string to t...

To have the check box checked by default, pass either :checked => true or :checked => 'checked' in the options. See ActionView::Helpers::InstanceTag#to_check_box_tag for details.

ActionController::Caching::Sweeping

When defining a has_many relationship this behaviour is on by default. See has_many documentation, look for the :validate flag.

Allows you to specify indices to add in a migration that will only be created if they do not

# already exist, or to remove indices only if they already exist with :quiet=>true
module ActiveRecord::ConnectionAdapters::SchemaStatements
def add_index_with_quiet(table_name, column_nam...

You want to use a mock when you're testing a behaviour of one of your methods that interacts with some outside world service (eg. an FTP server).

it "should login to ftp server" do ftp = mock('Ftp server', :null_object => true) Net::FTP.should_receive(:new).and_return(ftp) ftp.sho...

If you'd like to specify a respond_to only for 1 or a few formats and render something else for all other formats, eg: (action.rss returns a feed but action.html or action.js should just render 404), use format.all:

respond_to do |format| format.rss { render_rss } format.all { render_4...

==== Ruby style Dir[File.join(RAILS_ROOT, 'vendor', 'plugins', '')] ==== Rails style Dir[Rails.root.join('vendor', 'plugins', '')]

This method has a security hole in Rails 2.3.2. See http://weblog.rubyonrails.org/2009/6/3/security-problem-with-authenticate_with_http_digest for explanation.

Rails 2.3.3 should fix the problem.

You may have this exception raised if any of the defined callbacks such as ActiveRecord::Base#before_save or ActiveRecord::Base#before_create return false.

This can happen accidentally. For example:

class MyModel < ActiveRecord::Base
before_save :assign_default_foo

protected
d...

As of 0349278f3da9f7f532330cf295eed35ede3bae66 cookie updates will persist in the current request.

====

validates_uniqueness_of :name, :scope => [:big_category_id, :small_category_id]

SELECT * FROM schedules WHERE (products.name = 'xxxx' AND products.big_category_id= 1 AND products.small_category_id = 1) LIMIT 1

I created a helper method to access some meta data using

def [](name)
# do stuff
end

This breaks ActiveRecord behaviors. all belongs_to relations were broken

eg.

class Image
belongs_to :album
end

i = Image.find :first
i.album_id # 1
i.album # nil

Album...