How to mock/stub the config initializer hash in rails 3 - ruby-on-rails-3.1

Question

Environment : Rails 3.1.1 and Rspec 2.10.1
I am loading all my application configuration through an external YAML file. My initializer (config/initializers/load_config.rb) looks like this
AppConfig = YAML.load_file("#{RAILS_ROOT}/config/config.yml")[RAILS_ENV]
And my YAML file sits under config/config.yml
development:
client_system: SWN
b2c_agent_number: '10500'
advocacy_agent_number: 16202
motorcycle_agent_number: '10400'
tso_agent_number: '39160'
feesecure_eligible_months_for_monthly_payments: 1..12
test:
client_system: SWN
b2c_agent_number: '10500'
advocacy_agent_number: 16202
motorcycle_agent_number: '10400'
tso_agent_number: '39160'
feesecure_eligible_months_for_monthly_payments: 1..11
And I access these values as, For example AppConfig['feesecure_eligible_months_for_monthly_payments']
In one of my tests I need AppConfig['feesecure_eligible_months_for_monthly_payments'] to return a different value but am not sure how to accomplish this. I tried the following approach with no luck
describe 'monthly_option_available?' do
before :each do
#policy = FeeSecure::Policy.new
#settlement_breakdown = SettlementBreakdown.new
#policy.stub(:settlement_breakdown).and_return(#settlement_breakdown)
#date = Date.today
Date.should_receive(:today).and_return(#date)
#config = mock(AppConfig)
AppConfig.stub(:feesecure_eligible_months_for_monthly_payments).and_return('1..7')
end
.....
end
In my respective class I am doing something like this
class Policy
def eligible_month?
eval(AppConfig['feesecure_eligible_months_for_monthly_payments']).include?(Date.today.month)
end
....
end
Can someone please point me in the right direction!!

Answer 1

The method that is being called when you do AppConfig['foo'] is the [] method, which takes one argument (the key to retrieve)
Therefore what you could do in your test is
AppConfig.stub(:[]).and_return('1..11')
You can use with to setup different expectations based on the value of the argument, ie
AppConfig.stub(:[]).with('foo').and_return('1..11')
AppConfig.stub(:[]).with('bar').and_return(3)
You don't need to setup a mock AppConfig object - you can stick your stub straight on the 'real' one.