Support splay nil to disable splay behavior

.rubocop.yml

@@ -6,6 +6,9 @@ AllCops:
   SuggestExtensions: false
   TargetRubyVersion: 2.7
 
+Gemspec/DevelopmentDependencies:
+  Enabled: false
+
 Layout/ParameterAlignment:
   EnforcedStyle: with_fixed_indentation
 Layout/CaseIndentation:

lib/amigo/scheduled_job.rb

@@ -22,11 +22,12 @@ def logger
       end
 
       def perform(*args)
-        if args.empty?
+        splay = self.class.splay_duration
+        if splay.nil? || args == [true]
+          self._perform
+        elsif args.empty?
           jitter = rand(0..self.class.splay_duration.to_i)
           self.class.perform_in(jitter, true)
-        elsif args == [true]
-          self._perform
         else
           raise "ScheduledJob#perform must be called with no arguments, or [true]"
         end
@@ -62,6 +63,16 @@ def cron(expr)
         self.cron_expr = expr
       end
 
+      # When the cron job is run, it is re-enqueued
+      # again with a random offset. This splay prevents
+      # the 'thundering herd' problem, where, say, may jobs
+      # are meant to happen at minute 0. Instead, jobs are offset.
+      #
+      # Use +nil+ to turn off this behavior and get more precise execution.
+      # This is mostly useful for jobs that must run very often.
+      #
+      # +duration+ must respond to +to_i+.
+      # @param duration [Integer,#to_i]
       def splay(duration)
         self.splay_duration = duration
       end

spec/amigo/amigo_spec.rb

@@ -293,6 +293,22 @@ def _perform
       expect(args).to eq([true] * 20)
     end
 
+    it "executes immediately when splay is nil" do
+      calls = []
+      job = Class.new do
+        extend Amigo::ScheduledJob
+        cron "* * * * *"
+        splay nil
+        define_method(:_perform) do
+          calls << true
+        end
+      end
+
+      expect(job).to_not receive(:perform_in)
+      Array.new(20) { job.new.perform }
+      expect(calls).to eq([true] * 20)
+    end
+
     it "executes its inner _perform when performed with true" do
       performed = false
       job = Class.new do