Figuring out the plan to write an RSpec test - ruby-on-rails

Question

I have a controller as following:
class ReportsController < ApplicationController
respond_to :html
def show
client = ReportServices::Client.new(ServiceConfig['reports_service_uri'])
#report = client.population_management(params[:id])
if #report
#kpis = #report[:key_performance_indicators]
#populations = #report[:population_scores]
#population_summaries = #report[:population_summaries]
#providers = #report[:provider_networks]
end
respond_with (#report)
end
end
Which I want to write a RSpec test for it but have no clue where to start from, I guess because it has that URL in it, it makes it harder for me, I am pretty new to Rails and RSpec and have some basic knowledge of writing RSpec for my Models but this one has puzzled me for the whole weekend.

Answer 1

So the first thing to tackle is mocking the external API request. The general idea here is that your going to return a mock object from new that will respond to population_management and return what you expect for #report.
describe ReportsController do
before do
#report_data = {
:key_performance_indicators => 'value',
:population_scores => 'value',
:population_summaries => 'value',
:provider_networks => 'value'
}
# This will fake the call to new, return a mock object that when
# population_management is called will return the hash above.
#fake_client = double(:population_management => #report_data)
ReportServices::Client.stub(:new => #fake_client)
end
describe '#show' do
it 'assigns #report' do
get :show, id: 1
assigns(:report).should == #report
end
it 'assigns some shortcut vars' do
[:kpis, :populations, :population_summaries, :providers].each do |var|
assigns(var).should_not be_nil
end
end
# and whatever else you'd like
end
end

Answer 2

You can stub the client interface to write an isolated test of your controller.
describe RerpotsController do
it "assigns a new report as #report" do
expected_id = '1234'
expected_kpi = 'kpi'
report = { key_performance_indicators: expected_kpi, ... }
client = double(ReportServices::Client)
client.should_receive(:population_management).with(expected_id) { report }
ReportServices::Client.should_receive(:new) { client }
get :show, id: expected_id
assigns(:kpis).should eq(expected_kpi)
# ...
end
end
You probably don't need to unpack the report in the controller.