Corrects a minor bug in ScheduledExecution

ScheduledExecution#dispatch_next_batch was returning either an empty
array or an integer count of the number of rows processed by the method.
The client of this method is Worker and Dispatcher #poll, and poll
requires the count of the number of rows processed.

This commit changes the returned empty array to an integer value of 0
for consistency’s sake.  It also includes small updates to the tests
for these methods.

Author: hms

app/models/solid_queue/scheduled_execution.rb

@@ -14,7 +14,8 @@ class << self
       def dispatch_next_batch(batch_size)
         transaction do
           job_ids = next_batch(batch_size).non_blocking_lock.pluck(:job_id)
-          if job_ids.empty? then []
+          if job_ids.empty?
+            0
           else
             SolidQueue.instrument(:dispatch_scheduled, batch_size: batch_size) do |payload|
               payload[:size] = dispatch_jobs(job_ids)

test/unit/dispatcher_test.rb

@@ -96,6 +96,7 @@ class DispatcherTest < ActiveSupport::TestCase
     dispatcher = SolidQueue::Dispatcher.new(polling_interval: 10, batch_size: 1)
     dispatcher.expects(:interruptible_sleep).with(0.seconds).at_least(3)
     dispatcher.expects(:interruptible_sleep).with(dispatcher.polling_interval).at_least_once
+    dispatcher.expects(:handle_thread_error).never
 
     3.times { AddToBufferJob.set(wait: 0.1).perform_later("I'm scheduled") }
     assert_equal 3, SolidQueue::ScheduledExecution.count
@@ -112,8 +113,10 @@ class DispatcherTest < ActiveSupport::TestCase
     dispatcher = SolidQueue::Dispatcher.new(polling_interval: 10, batch_size: 1)
     dispatcher.expects(:interruptible_sleep).with(0.seconds).never
     dispatcher.expects(:interruptible_sleep).with(dispatcher.polling_interval).at_least_once
+    dispatcher.expects(:handle_thread_error).never
+
     dispatcher.start
-    sleep 0.1
+    wait_while_with_timeout(1.second) { !SolidQueue::ScheduledExecution.exists? }
   end
 
   private

test/unit/worker_test.rb

@@ -176,6 +176,7 @@ class WorkerTest < ActiveSupport::TestCase
 
     @worker.expects(:interruptible_sleep).with(10.minutes).at_least_once
     @worker.expects(:interruptible_sleep).with(@worker.polling_interval).never
+    @worker.expects(:handle_thread_error).never
 
     @worker.start
     sleep 1.second
@@ -186,6 +187,7 @@ class WorkerTest < ActiveSupport::TestCase
 
     @worker.expects(:interruptible_sleep).with(@worker.polling_interval).at_least_once
     @worker.expects(:interruptible_sleep).with(10.minutes).never
+    @worker.expects(:handle_thread_error).never
 
     @worker.start
     sleep 1.second