couchdb_initializer.rb

# You can override these if you want in environment initializers:
COUCHDB_HOST = 'http://127.0.0.1:5984' unless defined?(COUCHDB_HOST)
COUCHDB_DB_NAME = "learnhub_#{Rails.env}" unless defined?(COUCHDB_DB_NAME)

# This stuff should stay here:
COUCHDB_SERVER = CouchRest.new(COUCHDB_HOST)
COUCHDB_DATABASE = COUCHDB_SERVER.database!(COUCHDB_DB_NAME)
CouchRest::Model.default_database = COUCHDB_DATABASE

stack_trace.txt

NoMethodError (You have a nil object when you didn't expect it!
The error occurred while evaluating nil.view):
    /opt/local/lib/ruby/gems/1.8/gems/jchris-couchrest-0.12.2/lib/couchrest/core/design.rb:84:in `fetch_view'
    /opt/local/lib/ruby/gems/1.8/gems/jchris-couchrest-0.12.2/lib/couchrest/core/design.rb:42:in `view'
    /opt/local/lib/ruby/gems/1.8/gems/jchris-couchrest-0.12.2/lib/couchrest/core/model.rb:392:in `fetch_view'
    /opt/local/lib/ruby/gems/1.8/gems/jchris-couchrest-0.12.2/lib/couchrest/core/model.rb:383:in `fetch_view_with_docs'
    /opt/local/lib/ruby/gems/1.8/gems/jchris-couchrest-0.12.2/lib/couchrest/core/model.rb:346:in `view'
    /opt/local/lib/ruby/gems/1.8/gems/jchris-couchrest-0.12.2/lib/couchrest/core/model.rb:327:in `method_missing'
    /lib/user_update_methods.rb:12:in `latest_update'

user_update.rb

class UserUpdate < CouchRest::Model

  class ValidationError < StandardError; end

  unique_id :slug

  key_reader :slug
  key_accessor :timestamp
  key_accessor :user_id
  key_accessor :user_username
  key_accessor :body

  view_by :slug, :descending => true
  view_by :user_id, :descending => true

  before :save, :validate
  before :save, :create_and_set_slug
  before :save, :compress_links_in_body
  after :save, :increment_user_counter_cache
  after :destroy, :decrement_user_counter_cache

  def self.build(attrs = {})
    user = attrs.delete(:user)
    if user
      attrs[:user_id] = user.id
      attrs[:user_username] = user.username
    end
    new attrs
  end

  def dom_id
    new_document ? 'new_user_update' : "user_update_#{user_username}_#{timestamp}"
  end

  def created_at
    Time.at(timestamp.to_i)
  end

  def to_s
    body
  end

  private

  def validate
    raise ValidationError, 'User ID is required to store document.' if self['user_id'].blank?
    raise ValidationError, 'Username is required to store document.' if self['user_username'].blank?
    raise ValidationError, 'Your update can not be blank.' if self['body'].blank?
    raise ValidationError, 'Your update may not exceed 140 characters.' if self['body'].length > 140
  end

  def compress_links_in_body
    self['body'] = Bitly.compress_urls_in(body)
  end

  def increment_user_counter_cache
    User.async_execute(:increment_user_updates_count, self['user_id']) if new_document?
  end

  def decrement_user_counter_cache
    User.async_execute(:decrement_user_updates_count, self['user_id'])
  end

  def create_and_set_slug
    self['timestamp'] = Time.now.to_i if new_document? && !self['timestamp']
    self['slug'] = "#{self['user_username']}/#{self['timestamp']}" if new_document?
  end

end

user_update_methods.rb

# These are mixed in to my User class (which an ActiveRecord model)

module UserUpdateMethods

  def user_update_by_timestamp(timestamp)
    UserUpdate.get("#{username}/#{timestamp}")
  end

  def user_updates
    UserUpdate.by_user_id(:key => id)
  end

  def latest_update
    UserUpdate.by_user_id(:key => id, :limit => 1).try(:first)
  end

  def create_user_update(attrs)
    raise ArgumentError, "attrs must be a Hash, not: #{attrs.class}" unless attrs.is_a?(Hash)
    attrs.symbolize_keys!
    uu = UserUpdate.build(:user => self, :body => attrs[:body])
    uu.save
    uu
  end

end

user_update_test.rb

require 'test/unit/../test_helper'


class UserUpdateTest < ActiveSupport::TestCase

  context 'UserUpdate.get' do
    context 'for an existing document' do
      setup do
        refresh_test_data!
        @user_update = UserUpdate.get('cnielsen/1000000003')
      end

      should 'return the document as an instantiated UserUpdate object' do
        assert_instance_of UserUpdate, @user_update
      end

      should 'return the document that was requested' do
        assert_equal 'cnielsen/1000000003', @user_update['slug']
      end
    end

    context 'for a non-existing document' do
      should 'raise an error' do
        assert_raise RestClient::ResourceNotFound do
          UserUpdate.get('cnielsen/0')
        end
      end
    end
  end


  context 'A user with many updates' do
    setup do
      refresh_test_data!
      @user = users(:cnielsen)
    end

    should 'have many user_updates' do
      deny_empty @user.user_updates
    end

    should 'have a pesudo #user_update_by_timestamp method for UserUpdate.get' do
      assert_equal 'Update 5.', @user.user_update_by_timestamp('1000000004').body
    end

    should 'have a #latest_update method that returns the latest update' do
      assert_equal 'cnielsen/1000000004', @user.latest_update.slug
    end
  end


  context 'A UserUpdate instance' do
    context 'with valid attributes' do
      setup do
        reset_couchdb!
        @user_update = UserUpdate.build(
          :user => users(:cnielsen),
          :body => 'CouchDB is fantastic!')
      end

      should 'save without any problems' do
        assert_nothing_raised { @user_update.save }
        assert_nothing_raised { @user_update.destroy }
      end

      should 'have a timestamp automatically set after being saved' do
        assert_nothing_raised { @user_update.save }
        assert_instance_of Bignum, @user_update.timestamp
      end
    end

    context 'with no username' do
      setup do
        @user_update = UserUpdate.build(
          :body => 'CouchDB is wicked sexy!')
      end

      should 'raise a ValidationError on save' do
        assert_raise(UserUpdate::ValidationError) { @user_update.save }
      end
    end

    context 'with no body' do
      setup { @user_update = UserUpdate.build(:user => users(:cnielsen)) }
      should 'raise a ValidationError on save' do
        assert_raise(UserUpdate::ValidationError) { @user_update.save }
      end
    end
  end

  private

  def refresh_test_data!
    reset_couchdb!
    carsten = User.find(2)
    wes = User.find(1)
    john = User.find(3)
    [ { :user => carsten, :body => 'Update 1.', :timestamp => 1000000000 },
      { :user => carsten, :body => 'Update 2.', :timestamp => 1000000001 },
      { :user => carsten, :body => 'Update 3.', :timestamp => 1000000002 },
      { :user => carsten, :body => 'Update 4.', :timestamp => 1000000003 },
      { :user => carsten, :body => 'Update 5.', :timestamp => 1000000004 },
      { :user => wes, :body => 'Update 1.', :timestamp => 1000000000 },
      { :user => wes, :body => 'Update 2.', :timestamp => 1000000001 },
      { :user => wes, :body => 'Update 3.', :timestamp => 1000000002 },
      { :user => wes, :body => 'Update 4.', :timestamp => 1000000003 },
      { :user => john, :body => 'Update 1.', :timestamp => 1000000000 },
      { :user => john, :body => 'Update 2.', :timestamp => 1000000001 },
      { :user => john, :body => 'Update 3.', :timestamp => 1000000002 }
    ].each { |u| UserUpdate.build(u).save }
  end

end