Rake task testing with Rspec

report.rake

namespace :report do
  task :daily => :environment do
    report_for_all_users('daily_report', 'day')
  end

  def report_for_all_users(flag, time_period)
    puts "Getting users who want #{flag.to_s.humanize}s"
    users = User.where("admin = true AND settings -> '#{flag}' = '1'")
    puts "Sending #{flag.to_s.humanize}s for #{users.count} users"
    users.each do |user|
      puts "Sending report for #{user.name}"
      Report.generate_and_send(user, time_period)
    end
    puts "#{flag.to_s.humanize}s sent!"
  end
end

report_rake_spec.rb

require 'rspec'
require 'spec_helper'
require 'rake'

describe 'report namespace rake task' do
  describe 'report:daily' do
    let!(:account) { Fabricate(:account) }
    let!(:user1) { Fabricate(:user, account: account, admin: true) }
    let!(:user2) { Fabricate(:user, account: account, admin: true) }
    let!(:user3) { Fabricate(:user, account: account, admin: false) }

    before do
      load "tasks/report.rake"
      Rake::Task.define_task(:environment)
      user1.update(settings:
                  {'daily_report' => '1',
                  'weekly_report' => '1',
                  'monthly_report' => '1'})
      user2.update(settings:
                  {'daily_report' => '1',
                  'weekly_report' => '1',
                  'monthly_report' => '1'})
      user3.update(settings:
                  {'daily_report' => '1',
                  'weekly_report' => '1',
                  'monthly_report' => '1'})
    end

    it "should call the generate_and_send method" do
      Report.should_receive(:generate_and_send).with(user1, 'day')
      Report.should_receive(:generate_and_send).with(user2, 'day')
      Report.should_not_receive(:generate_and_send).with(user3, 'day')
      Rake::Task["report:daily"].invoke
      puts '{During Rspec run, no reports actually sent}'
    end
  end
end