Mongo::Fixture

Similar to Rails 2 fixtures, but for MongoDB (using the standard mongo connector Gem ).

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Single collection

Assuming you have a fixture for the collection messages with:

# test/fixtures/some_data/messages.yaml
yesterday_afternoon:
  text: Honey, pizza tonight?
  sent: 2012-09-11
today_morning:
  text: Nice date yesterday, how about next week?
  sent: 2012-09-12

You can write a brief ruby script and insert the data into your mongo db:

require 'mongo'
require 'mongo-fixture'

DB = Mongo::Connection.new.db 'messages-db' # An example connetion setup

# Insert the fixture into the database
fixture_some_data = Mongo::Fixture.new :some_data, DB

# You can now query the fixture for the data that was sent into the DB
fixture_some_data.messages.yesterday_afternoon.text # => "Honey, pizza tonight?"

The fixture is identified by the name of the folder containing the fixture YAML files. The default folder is test/fixtures.

As you can see, each record is preceded by a name, in this case yesterday_afternoon and today_morning. This names never get inserted into the database, they are just references for making it easier to access the fixture's information.

Associations

Assuming you have a fixture for the collection users with:

# test/fixtures/simple/users.yaml
john:
  name: John
  last_name: Doe
  email: [email protected]
jane:
  name: Jane
  last_name: Doe
  email: [email protected]

and for messages:

# test/fixtures/simple/messages.yaml
greeting:
  sender:
    users: john
  receiver:
    users: jane
  text: Hi Jane! Long time no see.
long_time:
  sender:
    users: jane
  receiver:
    users: john
  text: John! Long time indeed. How are you doing?

Mongo Fixture will automatically insert the object id (_id field in the database) for the referenced users. The Mongo Fixture syntax specifies that:

  sender:
    users: john

is a reference to the record named john in the collection users.

Currently Mongo Fixture does not support references from one collection to another and back from that collection to the first one.

For example given the ruby script:

# script.rb
require "mongo-fixture"

DB = Mongo::Connection.new.db 'mongo-test-db' # Just a simple example

fixture = Mongo::Fixture.new :simple, DB # Will load all the data in the fixture into the database

fixture.users               # == fixture[:users]
fixture.users.john.name     # => "John"
                            # The YAML files are parsed into a SymbolMatrix
                            # http://github.com/Fetcher/symbolmatrix

fixture.rollback            # returns users and messages to pristine status (#drop)


fixture = Mongo::Fixture.new :simple, DB, false    # The `false` flag prevent the constructor from automatically pushing
                                                   # the fixture into the database

fixture.check               # Will fail if the user or messages collection
                            # were already occupied with something

fixture.push                # Inserts the fixture in the database

fixture.rollback            # Don't forget to rollback

...naturally, mongo-fixture makes a lot more sense within some testing framework.

Many to many associations

As is custom in Mongo, a many-to-many association is implemented by passing an array of ids to a field in any of the records to associate. Mongo Fixture supports this. For example:

message:
  sender:
    users: john
  receivers:
    users: [mary, sue, harry, jack]
  text: Meeting tonight guys?

will insert into the receivers field an array with the _ids of the referenced users.

Changing fixtures directory

require 'mongo-fixture'

Mongo::Fixture.path = 'fixtures' # Now fixtures will be required from `fixtures/`

Installation

gem install mongo-fixture

Or using Bundler

gem 'mongo-fixture'

And then execute:

bundle

Future

Dump from a database to fixtures! This would be awesome.

License

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.