Fix: Next performing time should be related to last performing time

lib/crono/job.rb

@@ -2,17 +2,19 @@ module Crono
   class Job
     attr_accessor :performer
     attr_accessor :period
+    attr_accessor :last_performed_at
 
     def initialize(performer, period)
       self.performer, self.period = performer, period
     end
 
     def next
-      period.next
+      period.next(since: last_performed_at)
     end
 
     def perform
       Crono.logger.info "Perform #{performer}"
+      self.last_performed_at = Time.now
       Thread.new { performer.new.perform }
     end
   end

lib/crono/period.rb

@@ -5,8 +5,9 @@ module Crono
       @at_hour, @at_min = parse_at(at) if at
     end
 
-    def next
-      @period.from_now.change({hour: @at_hour, min: @at_min}.compact)
+    def next(since: nil)
+      since ||= Time.now
+      @period.since(since).change({hour: @at_hour, min: @at_min}.compact)
     end
 
     def parse_at(at)

spec/period_spec.rb

@@ -30,6 +30,11 @@ describe Crono::Period do
           @period = Crono::Period.new(2.day, at: 1)
         }.to raise_error("Unknown 'at' format")
       end
+
+      it "should return time in relation to last time" do
+        @period = Crono::Period.new(2.day)
+        expect(@period.next(since: 1.day.ago)).to be_eql(1.day.from_now)
+      end
     end
   end
 end