Testing ActiveRecord models inside a gem?

Question

I'm trying to extract a set of models from a Rails 3.2.3 app into a gem so they can be used as a shared interface between applications. I moved the model into a module and put it in lib/invite_interface/invite.rb ``` module InviteInterface class Invite < ActiveRecord::Base belongs_to :user end def to_json; end; def from_json; end; end ``` I plopped rspec into the gemfile, got it running successfully, created the following spec: ``` require 'spec_helper' describe InviteInterface::EncounterSurvey do it 'should belong to user' do subject.should respond_to(:user) end end ``` Unfortunately, I can't execute rspec on the model, because active record/rspec wants an active connection. ``` 1) InviteInterface::Invite should belong to encounter survey set Failure/Error: subject.should respond_to(:user) ActiveRecord::ConnectionNotEstablished: ActiveRecord::ConnectionNotEstablished # /Users/justin/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/activerecord-3.2.3/lib/active_record/connection_adap…

Accepted Answer

You need to test your library with a database anyway, so you might as well use an in-memory SQLite database for testing. Just add this to `spec_helper.rb`:

```
ActiveRecord::Base.establish_connection(:adapter => "sqlite3", 
                                       :database => ":memory:")
```

and create your schema as follows:

```
ActiveRecord::Schema.define do
  self.verbose = false

create_table :invites, :force => true do |t|
    t.string :text
  end
  ...
end
```

Testing ActiveRecord models inside a gem?

Solution

Problem