Merge pull request #18 from sellect/feature/fix-dst-end-bug

Use ActiveSupport::Duration to apply time offsets

delayed_cron.gemspec

@@ -22,6 +22,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "simplecov"
   s.add_development_dependency "codeclimate-test-reporter", "~> 1.0.0"
   s.add_development_dependency "hashie"
+  s.add_development_dependency "pry-byebug"
 
   s.files         = `git ls-files`.split("\n")
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")

lib/delayed_cron.rb

@@ -1,3 +1,4 @@
+require 'active_support/all'
 require 'delayed_cron/jobs'
 require 'delayed_cron/scheduling'
 require 'delayed_cron/railtie'

lib/delayed_cron/cron_job.rb

@@ -38,15 +38,15 @@ def convert_time_string_to_seconds_interval(scheduled_time_string, zone_name)
       zone = Time.find_zone!(zone_name)
 
       if hourly?
-        period_in_seconds = 60 * 60
+        period_duration = 1.hour
         scheduled_time_string = "%H:#{scheduled_time_string}"
       else
-        period_in_seconds = 60 * 60 * 24
+        period_duration = 1.day
       end
 
       scheduled_time = zone.now.strftime("%Y-%m-%d #{scheduled_time_string}")
       scheduled_time = zone.parse(scheduled_time)
-      scheduled_time += period_in_seconds if zone.now >= scheduled_time
+      scheduled_time += period_duration while zone.now >= scheduled_time
       scheduled_time.to_i - zone.now.to_i
     end
 

spec/cron_job_spec.rb

@@ -76,8 +76,11 @@ module DelayedCron
       let(:next_occurrence) do
         job.send(:convert_time_string_to_seconds_interval, scheduled_time, "Eastern Time (US & Canada)")
       end
+      let(:zone) { Time.find_zone!("Eastern Time (US & Canada)") }
+
       # Set Time.now to January 1, 2014 12:00:00 PM
       before { Timecop.freeze(Time.utc(2014, 1, 1, 12, 0, 0)) }
+
       context "next occurrence is today" do
         let(:known_interval) { 21600 }
         let(:scheduled_time) { "13:00:00 -0500" }
@@ -132,6 +135,35 @@ module DelayedCron
 
           expect(next_occurrence).to be(known_interval)
         end
+
+        it 'handles DST end' do
+          time = zone.local(2017, 11, 5, 1, 0) + 1.hour # ST start
+          Timecop.freeze(time)
+
+          expect(next_occurrence).to eq(1.hour.to_i)
+        end
+      end
+
+      context 'DST ends before next time' do
+        let(:scheduled_time) { "00:05:00" }
+
+        it 'adds an extra hour to the offset' do
+          time = zone.local(2017, 11, 5, 0, 5)
+          Timecop.freeze(time)
+
+          expect(next_occurrence).to eq(25.hours.to_i)
+        end
+      end
+
+      context 'calculation is on day of DST end' do
+        let(:scheduled_time) { "00:05:00" }
+
+        it 'still calculates correct offset' do
+          time = zone.local(2017, 11, 5, 23, 5)
+          Timecop.freeze(time)
+
+          expect(next_occurrence).to eq(1.hour.to_i)
+        end
       end
 
     end