ORMs

Transactions

Blueprints by default is transactional, meaning that before every test transaction is started and after every test that transaction is dropped which resets database to the state before the test. This state is empty database + any scenarios that you specify in enable_blueprints.

Sometimes using transactions is not possible (eg. using MongoDB or in cucumber scenarios). In that case you can turn off transactions when enabling Blueprints. Be aware though that disabling transactions on relational databases is quite a major performance loss.

ORM support

Blueprints is not tied to any ORM, however it does use Database Cleaner gem which currently supports Active Record, Data Mapper, Mongo Mapper, Mongoid and Couch Potato.

Active Record

Blueprints support Active Record >= 2.3 (yes that includes 3.0). Lower versions are not supported due to lack of nested transactions, however they should probably work without transactions. Class and instance 'blueprint' method is added to all models.

Mongoid

Blueprints was tested with Mongoid 2.0 only. It does support lower versions, but 'blueprint' method might not be available prior 2.0.

Mongo Mapper

Tested with Mongo Mapper 0.8.4, but should work with all prior versions too. Class and instance 'blueprint' method is added to all models.

Data Mapper

Is not fully supported (does not work with transactions). Maybe some Data Mapper guru can help me with that? Class and instance 'blueprint' method is added to all models.

Other ORMs and not ORMs

If you're using some other ORM (except Couch Potato) you will need to manually clean database before all tests. If you want to have blueprint method in your models you should take a look at Blueprints::Extensions modules (I will gladly help adding support to other ORMs).