TDD: Rspec Ruby MongoDB/Ruby Mongo Driver - ruby-on-rails-3

Question

how can I use TDD with MongoDB as my second database?
Thanks
Edit:
Using Rspec or anything else that allows me to test it.

Answer 1

[Update]
With MongoMapper set up you can easily use the mongodb connection directly
mongodb = MongoMapper.database
collection = mongodb.collection("my_collection")
collection.find.first
=> {"_id"=>BSON::ObjectId('4e43dfc75d1e1e0001000001'), "key1"=>"val1" }
this other SO Q/A is even more direct, using javascript functions like MongoMapper.database.eval(Mongo::Code.new('function(){ return 11 + 6; })
[/update]
I have such a polyglot architecture, some models with postgresql, others as mongo documents. I'm not really sure what you're asking, so I'll jump straight in and post most my configuration here. It includes my hacks, you probably find more beautiful config elsewhere.
I put the setup in a gist
https://gist.github.com/957341
OK, so here's a document with embedded document, then the spec. I wrote the specs one by one, so they're kinda test driven.
class MyDocument
include MongoMapper::Document
key :title, String
key :published_at, Time, :index => true
key :collaborators, Array
many :my_embedded_documents
end
class MyEmbeddedDocument
include MongoMapper::EmbeddedDocument
key :title, String
key :author, String
embedded_in :my_document
end
the spec
require "spec_helper"
describe MyDocument do
before do
#md = MyDocument.create(:title => "Example", :collaborators => ["mongomapper", "rspec", "oma"] )
end
it "should have title" do
found = MyDocument.find(#md.id)
found.title.should == "Example"
end
it "should have two my_documents" do
MyDocument.create
MyDocument.count.should == 2
end
it "should be able to fetch embedded documents" do
#md.my_embedded_documents << MyEmbeddedDocument.new(:title => "The King", :name => "Elvis Presley")
#md.my_embedded_documents.build(:title => "Embedded example", :name => "Embeddo")
#md.save!
MyDocument.where(:title => "Example").first.should == #md #findMyEmbeddedDocument.count.should == 2
end
end
spec_helper.rb
RSpec.configure do |config|
#...
config.after(:each) do
MongoMapper.database.collections.each(&:remove)
end
end
I don't know what you wanted for answers, but I hope this will be of help to somebody.

Answer 2

From what I can gather, it doesn't appear that your app is sticking to the rails MVC paradigm with its use of this secondary database that apparently doesn't store model data.
I would recommend taking the auxiliary parts of the app that depend on mongo and sticking them into a library. You can make this a gem if it makes sense to use it elsewhere. Then, create a testsuite for the logic of the library using standard testing tools, and integrate into your app either with a simple require, or some directives (depending on what it dies and how you intend to use it).