Testing rake tasks

This post continues our work in Improving our rake tasks with OOP.

In this one, we will discuss how to test our rake task; the example will be very straightforward. We will invoke the rake task and expect that some classes receive the correct arguments.

I will use Rspec as my test framework.

And I will continue with the same example from the last post.

require 'rake'

describe 'wunderground_daily rake task' do
  before(:each) do
    load File.expand_path('tasks/wunderground_daily.rake', __FILE__)
    Rake::Task.define_task(:environment)
  end

  after(:each) do
    Rake::Task.clear
  end

  context 'wunderground_daily:check_flights' do
    it 'call WeatherInformation with correct class and method' do
      expect(WeatherInformation).to receive(:get_weather_information).with(Pathify::Flight, :airport_destination)
      Rake::Task['wunderground_daily:check_flights'].invoke
    end
  end

  context 'wunderground_daily:check_trains' do
    it 'call WeatherInformation with correct class and method' do
      expect(WeatherInformation).to receive(:get_weather_information).with(Pathify::TrainReservation, :station_destination)
      Rake::Task['wunderground_daily:check_trains'].invoke
    end
  end
end

So the first we do is load rake, and we create a before block, which will be executed before every test. We load in memory the file where our tasks live, so the rake will know what task to execute. And we seat up the environment

The after block took some time to figure out why, but I was getting failing the tests because I was missing this one. Rake will store all the task that has been assigned, so the test where sharing the result, or so the expectation wasn’t met.

There is this great documentation for Rake; I really encourage you to look it Rake

Finally, in our test, we must invoke our task to execute it and see what results we get.

Also, because we previously refactored our rake, this test is easy to implement. I will continue this series of posts with a more complete one, focusing on testing.

Thanks for reading; if you have any comments, please don’t hesitate.