Deprecate eager-evaluated scopes.

Don't use this:

    scope :red, where(color: 'red')
    default_scope where(color: 'red')

Use this:

    scope :red, -> { where(color: 'red') }
    default_scope { where(color: 'red') }

The former has numerous issues. It is a common newbie gotcha to do
the following:

    scope :recent, where(published_at: Time.now - 2.weeks)

Or a more subtle variant:

    scope :recent, -> { where(published_at: Time.now - 2.weeks) }
    scope :recent_red, recent.where(color: 'red')

Eager scopes are also very complex to implement within Active
Record, and there are still bugs. For example, the following does
not do what you expect:

    scope :remove_conditions, except(:where)
    where(...).remove_conditions # => still has conditions

1 files changed, 1 insertions, 1 deletions

diff --git a/activerecord/test/models/organization.rb b/activerecord/test/models/organization.rb
index 4a4111833f..72e7bade68 100644
--- a/activerecord/test/models/organization.rb
+++ b/activerecord/test/models/organization.rb
@@ -8,5 +8,5 @@ class Organization < ActiveRecord::Base
   has_one :author, :primary_key => :name
   has_one :author_owned_essay_category, :through => :author, :source => :owned_essay_category
 
-  scope :clubs, { :from => 'clubs' }
+  scope :clubs, -> { from('clubs') }
 end